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Is LASIK or Refractive Surgery an Option For Me?

Refractive Surgery

Are you tired of wearing glasses or contacts and considering corrective surgery? This article will briefly discuss the different options and how corrective surgery works!

Anatomy of the Eye

To understand how corrective surgery works, a basic understanding of the eye’s anatomy will be beneficial.

The eye has 3 major parts to it—the cornea, the lens, and the retina.

The cornea is the front structure of your eye. It is clear and overlays the pupil and colored part of the eye (iris). It consists of 5 layers—from the most outside layer to inside layer: epithelium, Bowman’s layer, Stroma, Descemet’s membrane, and the endothelium.

The lens is the middle part of the eye. It is a flexible structure that can change shape based on where you want to focus—far away or up close.

The retina is the very back of the eye. It is responsible for actually detecting light and transmitting it to the brain to form images.

Light has to be able to pass easily and undeviated through the cornea and lens to land properly on the retina. If the cornea and/or lens are misshaped, the light will not focus correctly on the retina and vision will appear blurry—hence the need for glasses or contact lenses.


How Does Refractive Surgery Work?

Refractive surgery works by a surgeon (ophthalmologist) restructuring your cornea. This can be accomplished a few different ways, but ultimately the surgeon will use a laser to cut and remove part of your cornea to make its’ shape optimal for your refractive error.

If you are farsighted (i.e. hyperopic) the surgeon will want to steepen the central part of your cornea, this can be accomplished by flattening (i.e. removing part of) the outer edges of your cornea.

If you are nearsighted (i.e. myopia) the surgeon will want to flatten (i.e. remove part of) the central portion of your cornea.


Am I a Candidate for Refractive Surgery?

There are many aspects of your eyes that must be considered prior to deciding if you are a candidate for refractive surgery.

Your cornea needs to be a certain thickness to allow the surgeon to manipulate the tissue without making it too thin.

You need to have a stable prescription—once you undergo refractive surgery it is much more difficult to perform a second surgery.

You must be at least over the age of 18 years old.

Your prescription must fall within certain parameters—parameters very upon different techniques.

Your eyes must be healthy and free of inflammation. Certain ocular diseases will disqualify you from this procedure.

Your eye doctor will evaluate you closely and weigh the pros and cons of the procedure.


Different Types of Refractive Surgery

There are three major types of refractive surgery to date. Over the years these techniques have been improved and perfected, whereas others have been discontinued due to complications.



PRK, or Photorefractive Keratectomy, is a procedure in which the cornea epithelium and Bowman’s membrane are removed with a laser, and the stroma is “shaved down” to create the optimal surface to correct for your prescription.

PRK has a longer post-operative recovery time (about 2 weeks) since the epithelium will need to regrow completely.

PRK is recommended for individuals who live especially active lifestyles or are in the military.



LASIK, or Laser-Assisted In Situ Keratomileusis, is also a procedure in which a laser is used to correct a patient’s vision by reshaping the cornea.

LASIK differs from PRK in the fact that a laser is used to create an epithelium and bowman’s layer “flap”. The surgeon lifts the flap to access the stroma and “shave it down” to create the optimal surface to correct for your prescription.

Since LASIK does not actually remove the epithelium and Bowman’s layer, it has a quicker recovery time of around 24 hours.



SMILE, or Small Incision Lenticule Extraction surgery, is the newest form of refractive surgery.

SMILE creates a very small incision—no flap is created. The epithelium and Bowman’s layer remain in tact and the stroma is shaved down to reshape the cornea to the optimal shape to correct for your prescription.


Common Questions About Refractive Surgery

Can I get refractive surgery if I am farsighted (hyperopic)? Yes! In the past hyperopes may have been excluded, but today techniques have improved greatly to include our hyperope friends as well.

Can I get refractive surgery if I have astigmatism? Yes! It’s a bit more complicated, and there is a limit to how much can be corrected, but astigmatism does NOT exclude you from refractive surgery.

Is it true that if I get refractive surgery I’ll never need glasses again? No! While the majority of people post-surgery will not require correction, a select few number of patients will still require glasses post-opt. Also, you will still need reading glasses with age as cataracts/the need for reading glasses are an issue with the lens, not the cornea. So, almost everyone will need glasses eventually (typically decades down the road) post-opt.

Is it true that I will be awake during surgery? Yes. You will be given a topical numbing drop so you will not feel anything, but you will be asked to stare at a target for a few seconds. The laser system will tract your eyes so that if you move slightly the system will shut down until proper focus is regained—this prevents the surgery from continuing in case of needing to sneeze or another reason in which focus is lost.

Since a laser is being applied to my eye, does the surgery burn? No! You won’t feel much of anything. The laser is perfectly focused so that it cannot hurt anything besides just reshaping your cornea.

After surgery I won’t need to see my eye doctor yearly, right? Wrong. You will need a few follow-ups with your eye doctor after the surgery, and then it is recommended that you continue to see your eye doctor yearly. Refractive surgery has the tendency to cause an increase in dry eye symptoms, which your eye doctor will be able to help you manage, if needed.

It is also very important to continue to have yearly eye exams to check the health of your eyes as your cornea is being altered during surgery and complications (while uncommon) do occur. The sooner these complications are caught, the better off the prognosis.


Our eye doctors at Eye Theory in Houston, TX excel in the prescription of contact lenses, glasses and various eye diseases.  Call our optometrist at 832.831.7386 or schedule an appointment online if you would like to learn more about LASIK and the types of refractive surgery.  Our eye doctor, Dr. Jonathan Tsao, provides the highest quality optometry services and eye exams in the Midtown, Downtown, Museum District, Montrose, East Downtown, and Southside Commons (Southside Place) vicinities of Houston, Texas.

When Should My Child’s First Eye Exam Be?

When it comes to your child’s health, it seems like there are hundreds of recommendations and doctors to visit—but when should your child begin to see an eye doctor?

The Eyes and Human Development

As noted before, we know there are many different recommendations out there. With our friend Dr. Google it can be hard to determine what exactly is the best schedule to follow and when to go to what doctor.

However, when you think about it more closely, proper eye health is required for good vision—if vision is poor it can make life quite difficult.

If your child has poor eyesight from birth—they likely will not be able to recognize that his or her vision is poor, as it is what they have always known. He or she will not be able to tell you that they cannot see well, but instead will think that is simply how the world looks.

Poor vision, therefore, can cause a child to struggle in more aspects in life than just school work. Thus, it is important to have a first eye exam prior to entering school-aged years.

Think about a toddler learning to walk. If he or she cannot see where they are going—this toddler may be afraid to walk around and ultimately come to avoid the task. The same can be applied to other aspects of life as well. If a young child cannot see effectively, they may not be able to recognize family members, feed themselves, play with toys, etc.

Essentially, your baby could be trying to learn how to encounter the world for the first time through extreme blur—this would be a difficult task for anyone to overcome, let alone a baby! This could prolong their developmental milestone track and cause parental stress and worry.

While you might think the most appropriate doctor to see is a developmental therapist, the solution could be as simple as your baby just needing a pair of glasses.

Pediatricians and Eye Exams

A common statement heard from many parents is that they take their children regularly to see pediatricians and the pediatrician performs a vision screening—so why is it recommended to take my child to see an eye doctor?

This is a very fair question. Pediatricians go through schooling to learn about the human body in its entirety. They go through medical school first, and then at least three additional years of schooling to specialize in patient care for the younger population.

The human body is extremely complex with many different moving parts that must be evaluated within a 20 minute exam slot. Thus, when your child sees a pediatrician, the doctor is doing a simple screening looking for major eye health problems (cancers, malformations, obvious eye turns, infections, etc.), and then moving on to the next test.

This of course is not to say that pediatricians are not doing enough—they are experts in children medical care of course! However, the eye is so complex that doctors of optometry spend 4 years studying just eyes, and look at so much more than just a glasses prescription! Why not leave the vision examination to a specialist who is trained to pick up on subtleties and has the proper equipment to conduct various tests specific solely to the eyes?

What do Eye Doctors do Special During Pediatric Eye Exams?

Eye doctors not only have more advanced and specialized equipment to evaluate children’s eyes, but they also go through special schooling to assess children’s eyes.

An infant eye exam begins with your typical history questions—asking about length of pregnancy, complications that occurred during birth, and if applicable, developmental milestones. It is important to come prepared with this information as this information is crucial for eye development timelines and can lead your eye doctor to watch more closely for subtle signs and changes in your baby’s eyes.

For example, a baby that was born prior to 37 weeks (pre-mature) is at higher risk for eye turns (called strabismus), refractive errors (i.e. will need correctional glasses), and other eye health problems. This is not absolute—so do not panic reading this! It is just another reason as to why it is important to visit an eye doctor early in life rather than waiting until school-aged years.

After the history, your eye doctor will look at your child’s eye alignment to evaluate if he or she has an eye turn and ensure the eye muscles are working properly.

Next, the eye doctor will look at your child’s light reflex. This is how eye doctors can look into a patient’s eyes and determine if he or she needs a glasses prescription without verbal feedback.

The eye doctor will hold some lenses in front of your child’s eyes while shining a light into them quickly. The light is reflected off the back surface of the eye. With lenses, the eye doctor is able to neutralize this light reflex to come up with the appropriate glasses prescription (if needed).

The last major test during an eye exam is dilation. Dilation is important because it allows the doctor to use a special magnifying lens to look into the back structures of the eye and ensure everything is healthy and has developed properly.

It is important to catch any disease early, while it may be unlikely for a major problem to be uncovered in your child, it is always better to be safe when it comes to your child’s health.

What are Abnormalities Eye Doctors May Find During the Eye Exam?

A large majority of children will get the all-clear and be perfectly healthy with no treatment necessary from their first eye exam. Your eye doctor will then give you an updated timeframe and likely will not need to see your child again until reaching the school-aged years, unless another concern comes up in the meantime.

There are, however, several different abnormalities that may be detected during your child’s initial eye exam—initiating treatment for said abnormalities will be a lifechanging improvement for your child.

One such abnormality could be the need for glasses. A child who cannot see well may lash out, anger easily, or appear to be developmentally delayed. This could simply be out of frustration due to seeing the world as a blurry mess.

Many children need glasses—especially in today’s world with a drastic rise in myopia (near-sightedness). If your child needs glasses it is nothing to panic about, and there are many great options for flexible, comfortable glasses even for babies!

Another reason as to why eye exams are crucial for your young ones is due to a problem called amblyopia. In short, amblyopia is caused by the brain “shutting off” one eye. It can be caused from one eye seeing well and the other eye seeing poorly, an eye turn, or a structural abnormality such as an excessively droopy eyelid or trauma.

The crucial years for eye development range from birth to about 7 years of age. During this time, if amblyopia is caught, there is a much better likelihood of treatment working to “turn the eye back on” and prevent permanent decreased vision in the problem eye.

Amblyopia can be tricky to detect because your child might appear to see well, as their good eye is taking lead and allowing them to see “alright”. Eye doctors are trained to watch very closely for this problem; the earlier it is caught the better the outcome is for your child.

Other problems eye doctors watch for are eye turns, cancers, glaucoma, and other retinal diseases (the retina is the back most structure of the eye responsible for transmitting vision from the eye to the brain).

At What Age is the Eye Exam Recommended for my Child?

A safe recommendation is for your child to have his or her first eye exam around 6 months of age. If the eye doctor sees a concern it is easy to initiate treatment at that time, or if it is something that should be monitored they may recommend you bring your child back in to see them every year.

If everything looks good at this initial visit, your doctor will likely recommend you return for your child’s next visit when they get closer to starting school—around the age of 4-5 years.

Once reaching school-age, it is recommended to bring your child in for an eye exam yearly. This is to watch for changes and initiate any necessary treatment as early as possible to prevent the issue from progressing.

Is There Anything I Should Watch for in my Child Before the Eye Exam?

As a parent we know you have many concerns and are quite busy. However, the following is a list of signs that indicate you should make an appointment with your local eye doctor:

  • Excessive squinting
  • Inability to focus on a target (toy, bottle, face, etc.)
  • Visible eye turn (can be constant or only seen sometimes)
  • Excessively droopy eyelids
  • If the black part of your child’s eye appears white (especially in pictures)

If you notice one or more of these signs in your child, it does not necessarily mean something is wrong, but could be a sign of something more serious going on. Your local eye doctor would be more than happy to see your little-one and make sure he or she is setup to live their happiest, most-successful life.

Our eye doctors at Eye Theory in Houston, TX excel in the prescription of contact lenses, glasses and diagnosis of various eye diseases.  Call our optometrist at 832.831.7386 or schedule an appointment online if you would like to learn more about a pediatric eye exam.  Our eye doctor, Dr. Jonathan Tsao, provides the highest quality optometry services and eye exams in the Midtown, Downtown, Museum District, Montrose, East Downtown, and Southside Commons (Southside Place) vicinities of Houston, Texas.

Important Glasses Measurements You Probably Don’t Know About

A pair of glasses is designed specifically for you. From the size of the frame to the resting position of your eyes within the lens, they can be customized precisely to provide you with the best vision possible.

This is important not only for vision, but also for aesthetic, comfort and functionality. Below are some of the measurements our opticians will take from you to help create the best glasses for your needs.


Pupillary Distance (PD)

This is the distance between the pupils of your eyes. More specifically, it is the measurement between your pupils, the black circle in the center of your eyes through which light enters.

This can be taken as a distance between the eyes or separate measurements for each eye. This distance can also vary depending on whether you are looking in the distance, at the computer, or up close for near tasks.

A tool called a pupillometer will often be used to determine these measurements. Additionally, precise markings of the pupil centers when you are wearing your frame of choice can also provide us with the numbers we need.


Glasses Measurements and Vertex Distance

This is the distance between the back surface of the glasses and the front of your eyes. It is often more important for those with higher prescriptions as the distance between the lenses and your eyes will affect the strength of the lenses.

The distance at which your eyes were tested in the exam room may differ from the frame you choose, and this can have a large impact on achieving optimal vision.

It is crucial for our opticians to measure the position of the lenses on your face and the specific distance between the lenses and your eyes to compensate for any differences.


Pantoscopic Tilt is the “Tilt” of Your Frame

The tilt of the glasses refers to the angle of the lenses in relation to your face vertically. Typically, the bottom of the lenses or frame will be angled towards your cheeks while the top of the frame is angled slightly away from your brow bone.

Ensuring that the tilt is appropriate and not too extreme in either direction is key for excellent comfort and vision. This is measured in-office using a special device that determines the angle of the lenses and can be adjusted on most frames to fit your face shape.


Face Wrap is the Frame Curvature

The face wrap refers to how curved the glasses frame is to the rest of the face. For example, those that want to use their glasses for sports or protection from wind would like to have high wrap to their glasses and lenses.

This is also measured in-office using a tool that determines the angle and extent that the frame is curving. Some lenses will not be able to handle large amounts of wrap due to a lack of flexibility.


The Fitting Height is Crucial

The vertical position of your eyes behind the glasses is also important. This measurement is crucial in patients with high prescriptions and particularly for those interested in progressive lenses.

This is because the wrong fitting height can interrupt the regions of the lens that are meant for optimal vision, specifically for near or distance vision, as the eyes may be sitting in the wrong spot. One of our opticians will determine the location of your eyes vertically and subsequently measure the height from the bottom of the frame.


Our eye doctors at Eye Theory in Houston, TX excel in the prescription of contact lenses, glasses and various eye diseases.  Call our optometrist at 832.831.7386 or schedule an appointment online if you would like to learn more about the various important glasses measurements our opticians utilize before finalizing your order.  Our eye doctor, Dr. Jonathan Tsao, provides the highest quality optometry services and eye exams in the Midtown, Downtown, Museum District, Montrose, East Downtown, and Southside Commons (Southside Place) vicinities of Houston, Texas.

Unique Glasses and Contact Lens Options

In addition to regular spectacles and contact lenses, there are a number of lesser known options for vision correction. These are often built for certain work or play activities or specific eye conditions. Read on to learn more about some of these unique options.


Photosensitive, Tinted, and Color Contact Lenses

Contact lenses are becoming more technologically advanced all the time as new materials and designs are experimented with. Recently, a product has been introduced that combines the technology of Transitions lenses into a soft contact lens. Transitions lenses are photochromic, which means they darken in response to ultraviolet (UV) waves that exist in sunlight.

Darkening in this way helps to limit UV exposure to the eyes and prevent excessive brightness on a sunny day. They do visibly darken in the sun, but they are not a replacement for a regular pair of dedicated sunglasses. These contact lenses can be highly useful for people who spend a lot of time outside or for athletes in outdoor sports.

There are also colored and tinted contact lenses, which serve different purposes. Colored lenses are for aesthetic means, subtly changing the outward appearance of the iris, which is the colored part of the eye. Depending on the interaction of the lens and iris colors, many appearances can result in the end.

Tinted contact lenses are for visual purposes. They can enhance the ability to discern color or contrast differences. They can also be used in people with low vision or other eye and brain conditions to aid visual comfort and reduce symptoms.

Protective or Task-Specific Goggles

Goggles can be used for many activities, usually for more physical ones where the goggles must be tightly held to the head and eyes.

Goggles are often utilized in sports for vision correction, eye protection, or both. They can be customized to suit whatever needs a patient desires. For example, swim or ski goggles can be built with your prescription in them and can be tinted according to your needs as well.

These lenses are also useful in work that poses a hazard to the eyes. Safety glasses, as well as goggles, can be customized with your prescription while also providing adequate eye protection.

Vocational or Avocational Lenses

There are also various customized solutions for work and play. You may know of the traditional bifocal lens design, where a visible line separates an upper lens area built with the distance prescription from a lower area for the near prescription. This same design can be used in several different ways.

For electricians and pilots, for example, the bifocal design can be inverted so that near correction is on the top, allowing the clear vision of fine details above the head, and distance correction is on the bottom. Trifocals can also be used, where an intermediate lined portion is built between the distance and near portions of the bifocal, for those that require correction at specific distances.

Finally, there are lenses specifically designed for a day on the golf course. Most of the lens is built for distance, but there is a small portion in the corner made for seeing the scorecard and the tee. Other special variations exist and can always be customized to suit your visual needs.


Our eye doctors at Eye Theory in Houston, TX excel in the prescription of contact lenses, glasses and various eye diseases.  Call our optometrist at 832.831.7386 or schedule an appointment online if you would like to learn more about some of our unique eyewear solutions.  Our eye doctor, Dr. Jonathan Tsao, provides the highest quality optometry services and eye exams in the Midtown, Downtown, Museum District, Montrose, East Downtown, and Southside Commons (Southside Place) vicinities of Houston, Texas.

Do You Have a Strong Glasses Prescription?

Glasses are incredibly important for individuals with high prescriptions. Without vision correction, the world would be a blur, and completing simple everyday tasks would be difficult.

Unfortunately, the higher the individual’s prescription, the more power needs to be put into the corrective lenses and the thicker and heavier the lenses will be.

Luckily, there are many tips for picking the most optimal set of glasses that will provide the best comfort. Listed below are some key factors to consider when purchasing a new pair of glasses with a high refractive error.

High Myopia (Nearsightedness or Minus Prescriptions)

The first step is often to pick a set of frames that you will enjoy wearing. Of course, color and trend are important but for high prescriptions, there are other important components to keep in mind. First of all, for minus lenses, the higher the prescription, the thicker the lenses will be at the edges.

For this reason, it is important to pick a frame that has thick enough outer edges to hold the lenses in place and also to hide some of the thickness. Avoid rimless or semi-rimless frames.

Thicker temple arms on the frames can also help to hide the thickness of the lenses. Another thing to consider is that the larger the frame, the thicker the edges will be. So, it will be optimal to pick small frame sizes rather than large frames.

It is also important to make sure that the center of the frames are close to where the individual’s eyes are in the frames. Avoid frames where the eyes are sitting too close to the center of the frame and decentered towards the nose. The frames should sit close to the face to ensure optimal clarity.

The lenses for high minus prescriptions are also very important as the weight of the lenses will make a big difference, as well as any distortion in the lenses.

The thickness of the lens can be optimized by selecting a higher refractive index, which refers to the material that is used to make the lens. The higher the index, the thinner and lighter the lens will be.

It is also important to ensure that the lens has scratch-resistant, anti-reflective, and impact-resistant coatings. An aspheric design in the lens is also helpful as it decreases distortion when viewing outside of the optical center of the lens. Most high-quality lens manufacturers will automatically incorporate this into their higher prescription lenses.

A rarely used design for very high minus powers is referred to as lenticulation. This means that the prescription is put into the center of the lens in a circular disc (“the aperture”), with a thinner lens surrounding it (“the carrier”).

This decreases the weight of the lens and thins the outer edges of the lens. Keep in mind the aesthetic of the lens may not be preferred but comfort may increase immensely.

High Hypermetropia (Farsightedness or Plus Prescriptions)

Similar to high myopes, high hypermetropes (or plus prescriptions) will also need to be careful with their frame and lens selection. The higher the prescription, the thicker the lens, although the thickness will be at the center of the lens.

When picking a frame, it is also important to select a smaller frame and ensure that the eyes are not decentered too much from the centers of the lenses.

For higher plus powers, lens selection will mainly center around ensuring that the lenses have an aspheric design. This will decrease lens weight, thickness, and distortion in the periphery.
It will also help the lenses look more cosmetically appealing. A high index would also be preferred as it will make the lenses thinner and lighter. Coatings are of course important as well to prevent chipping and improve cosmetic appeal (scratch-resistant, anti-reflective, and impact-resistant coatings). Lenticulation is also an option for plus lenses.


Our eye doctors at Eye Theory in Houston, TX excel in the prescription of contact lenses, glasses, and various eye diseases.  Call our optometrist at 832.831.7386 or schedule an appointment online if you would like to learn more about how we can help if you have a strong glasses prescription.  Our eye doctor, Dr. Jonathan Tsao, provides the highest quality optometry services and eye exams in the Midtown, Downtown, Museum District, and Southside Commons (Southside Place) vicinities of Houston, Texas.

Choosing the Right Lens Options for Your New Glasses

There are many materials, designs, coatings, and treatment options to consider when you are choosing lenses to go in your newest pair of glasses.  These seemingly simple decisions can have a huge impact on your satisfaction with your lenses.  At Eye Theory, our experienced opticians can help you navigate the overwhelming task of choosing new lenses.  We have also compiled a quick reference guide to help answer some frequently asked questions about lenses. 


What Lens Material Should I Choose for Glasses?

The material used to make your lenses can impact the optics and clarity of your vision.  One of the most commonly used materials is CR-39, a lightweight and cost-effective plastic material that delivers good optics and clear vision.  While CR-39 is a strong lens, it does not include any additional coatings or special properties.  Another popular lens choice is polycarbonate lenses.  Polycarbonate is a durable, shatter-resistant material.  Its protective properties make it ideal for children, and it also provides some UV protection.  For people with strong prescriptions who want to avoid thick lenses, a high index material should be considered.  High index lenses help reduce the thickness and weight of lenses, which makes them more comfortable and cosmetically appealing.  


What Lens Coatings Should I Consider?

After you decide on a lens material, you need to decide on any additional lens coatings or treatments that you need to make your lenses suit your needs.  The most popular option is an anti-reflective coating.  This special treatment reduces reflections from both the front and back surface of your lenses and helps to reduce glare and improve visual comfort.  If you are bothered by glare from overhead lights, oncoming headlights, or long hours at the computer, this coating should be considered.  It also helps improve the cosmetic appearance of lenses and makes your lenses less noticeable.  You may consider treatments such as scratch-resistant coatings or UV-blocking coatings, though many lens materials, such as polycarbonate lenses, already include these properties.  Another popular lens option is photochromatic treatment.  Photochromatic lenses are clear lenses that transition into tinted sunglass lenses when exposed to UV light.  Photochromatic lenses are a cost-effective way to avoid buying both regular glasses and prescription sunglasses.  Though they are great for efficiency, photochromatic lenses have some drawbacks.  In certain conditions, they can be slow to change back into a clear lens after coming inside on a sunny day, leaving you with tinted lenses for longer than desired.  Additionally, because car windows and windshields are designed to block UV rays, most photochromatic lenses will not work in a car.   If you are more interested in a pair of prescription sunglasses for your outdoor needs, you can choose to have polarized lenses.  This treatment is used in sunglasses to filter out horizontal reflecting rays.   This can significantly reduce glare and improve clarity, and many outdoorsmen favor this lens coating.  

A highly trained optician is invaluable when it comes to choosing lenses.  By learning about how you use your eyes, including your job, your hobbies, and your type of prescription, they can help make tailored recommendations so you are satisfied with your glasses.  


Our eye doctors at Eye Theory in Houston, TX excel in the prescription of contact lenses, glasses and various eye diseases.  Call our optometrist at 832.831.7386 or schedule an appointment online if you would like to learn more about lens.  Our eye doctor, Dr. Jonathan Tsao, provides the highest quality optometry services  and eye exams in the Midtown and Southside Commons (Southside Place) vicinities of Houston, Texas.


Presbyopia and Vision Changes As You Age

Most middle-aged adults experience vision changes related to a condition known as presbyopia.  Presbyopia results in the gradual loss of the ability to focus on near objects.  It is a normal age-related change that begins to occur around the early to mid-40s and continues throughout adulthood.  Though this vision condition can be frustrating, confusing, or even embarrassing at first, it is a completely normal occurrence and there are many different options to help correct the blurry near vision caused by presbyopia.  


What Causes Presbyopia?

The focusing system of the eye is what allows us to view objects that are up-close, far away, and all distances in-between.  In youth, the focusing system of the eye is robust and flexible, and can easily focus to a wide range of distances.  However, as we age, the focusing system becomes more rigid, making it more difficult to clearly view objects at a close distance.  The acquired rigidness of the focusing system is a normal, age-related change and has no impact on the overall health of the eye or visual system.  Presbyopia gradually worsens over time, and near objects will become blurrier and blurrier.


Symptoms of Presbyopia

The early symptoms of presbyopia can be confusing at first. One of the most common early signs of presbyopia is needing to hold objects further away than normal in order to see them clearly.  While holding objects further away may work temporarily, presbyopia causes progressively blurred near vision as time goes on.  It may be more difficult to focus on fine print, and near work may be accompanied by headaches or significant eye strain.  People who are naturally farsighted may experience the symptoms of presbyopia sooner and more severely, while those who are nearsighted typically do not notice the symptoms quiet as early in life. Unfortunately, the blurred vision caused by presbyopia cannot simply be fixed by “focusing harder.”  For most, this vision condition requires optical correction in order to clearly and comfortably see close objects again. 


Seeing Clearly with Presbyopia 

Luckily, there are many corrective options for those affected by presbyopia.  Many people choose to use reading glasses to help them see up-close, but these glasses need to be removed in order to see clearly far away.  For people interested in a single pair of glasses that can be worn full time, there are several different options that can provide clear vision for near and distance objects.  Lined bifocal lenses contain a distance prescription at the top of the lens, and a reading prescription at the bottom.  Similarly, progressive lenses, or “no-line bifocals,” contain a gradient of prescriptions to allow for clear vision at a range of distances.  Many people prefer these lens options in order to avoid putting on and removing glasses many times throughout the day.  There are even contact lens options for those affected by presbyopia that want to avoid glasses altogether.  Multifocal contact lenses are special soft lenses that provide correction for both distance and near vision.  They come in many different brands and designs, so almost all contact lens wearers can find a multifocal lens that works for them.  


Our eye doctor at Eye Theory in Houston, TX excels in the prescription of contact lenses, glasses and various eye diseases.  Call our optometrist at 832.831.7386 or schedule an appointment online if you would like to learn more about presbyopia.  Our eye doctor, Dr. Jonathan Tsao, provides the highest quality optometry services  and eye exams in Houston and Midtown Texas area.

Glasses and Refractive Error

There are several different vision conditions that require correction with glasses, contact lenses, or corrective surgery.  These conditions affect the way that light enters the eye, causing rays of light to incorrectly focus in front of or behind the retina.  Refractive error is the term used to describe these conditions that cause blurred or distorted vision.  These vision problems are relatively harmless and easily corrected by glasses or contact lenses to alter how light enters the eye, allowing light to properly focus on the retina and eliminating blurred vision.  Continue reading to learn more about refractive error and what to do if you are affected. 


The Rise of Myopia

Myopia is also referred to as nearsightedness.  This is a very common form of refractive error in which objects that are far away are blurred, but up-close objects are clearer and easier to see.  In myopia, light rays enter the eye and focus too far in front of the retina. This can occur because the front surface of the eye is too curved and alters the way light bends when it enters the eye, or it can occur because the eye is too long.  Most commonly, it is a combination of both of these attributes that leads to myopia. Nearsightedness is easily corrected by glasses or contact lenses that modify the way light enters the eye, pushing back light rays so they focus on the retina. The lenses used to correct for myopia are annotated with a “minus” value, such as -3.00.  Because nearsightedness is oftentimes caused by an elongated eyeball, those with moderate to high amounts of myopia are at a higher risk for retinal health problems such as retinal holes, tears, detachments, or even the development of glaucoma. Because of these risks, those with myopia should receive an annual eye examination that includes a retinal health evaluation. 


Hyperopia and Farsightedness

Farsightedness, or hyperopia, causes blurred vision, eyestrain, or eye fatigue while looking at up-close objects.  This occurs because light focuses too far behind the retina. In some people, especially children and young adults, the focusing system of the eye is strong enough to compensate for this form of refractive error.  But over time the focusing system weakens, and many people experience uncomfortable symptoms of hyperopia with extended near or up-close visual tasks. Most people become farsighted in their mid 40s due to a visual condition known as presbyopia.  Like myopia, both hyperopia and presbyopia can be corrected by glasses or contact lenses. Refractive surgery is less commonly used to treat or manage these vision conditions. 



An astigmatism refers to a visual condition in which the cornea, or the front surface of the eye, is not perfectly curved.  If one portion of the cornea is curved differently than another, it alters how light enters the eye and causes distorted or blurred vision while looking at objects that are both close up and far away.  Astigmatism is much more common than people think; in fact, almost everyone has some degree of astigmatism. This condition is just like myopia or hyperopia in that it is easily corrected by contact lenses or glasses.  


Our eye doctor at Eye Theory in Houston, TX excels in the prescription of contact lenses, glasses and various eye diseases.  Call our optometrist at 832.831.7386 or schedule an appointment online if you would like to learn more about your refractive error.  Our eye doctor, Dr. Jonathan Tsao, provides the highest quality optometry services  and eye exams in Houston and Midtown Texas area.

Digital Screens and Computer Vision Syndrome

For many people, extensive use of digital screens is an important part of maintaining a professional or personal life.  Unfortunately, extended and uninterrupted screen time using computers, tablets, or smart phones may cause a group of symptoms known as Computer Vision Syndrome or Digital Eye Strain.  The more time spent viewing digital screens, the worse the symptoms of this condition may be. Computer Vision Syndrome is becoming increasingly common. In fact, research suggests that the vast majority of people who use computers or other digital screens show some degree of symptoms associated with the condition. Continue reading to learn more about how Computer Vision Syndrome may be affecting your eyes. 


What are the Symptoms of Computer Vision Syndrome?

Computer Vision Syndrome, also called CVS, can cause a wide range of symptoms.  Most commonly, people affected by this condition can experience blurred vision, eye fatigue or strain, and dry uncomfortable eyes. In more severe cases, symptoms can include headaches or double vision.  Using digital screens late at night can also disrupt the body’s natural circadian rhythm and may result in difficulty sleeping. The more time spent using digital screens, the more likely the symptoms of Computer Vision Syndrome are to be severe and bothersome.  For some people, these symptoms improve when they stop using a screen, but for others the symptoms can persist long after screen use has stopped. Those people may need to turn to other options for relieving the symptoms of CVS.


Specialized Computer Glasses

Eyestrain and fatigue is one of the most common symptoms associated with prolonged computer use. These symptoms occur because working on a computer or other digital screens in close proximity creates a lot of extra work for the focusing system of the eye. If you frequently experience this eye strain, a prescription can be written for specialized computer glasses to help improve visual comfort.  A computer prescription can be determined during a comprehensive eye examination, and will take into account factors like your traditional glasses prescription and the distance you sit from your screen.  These glasses can be made in a wide variety of lens designs, including progressive or bifocal glasses for those who view digital screens at a range of distances. They can also incorporate blue-blocking lenses to reduce additional eye fatigue associated with screen use.   


Treating Digital Dryness

When we look at digital screens, we tend to blink less often than normal.  This reduced rate of blinking leads to uncomfortable symptoms of dryness and irritation.  To address these symptoms of CVS, ask your optometrist for recommendations for a lubricating eye drop.  These over-the-counter artificial tears can be used during and after using digital screens to nourish the front surface of the eye and reduce discomfort associated with prolonged screen use. 


Remember to Take a Break from Digital Screens

As we have discussed, using digital screens for a long period of time can place a burden on the focusing system of the eye.  In addition to specialized computer glasses, one way to reduce eyestrain associated digital screens is to periodically give your focusing system a break.  To do this, try following the “20-20-20 rule.” This rule states that for every 20 minutes, you should look at an object at least 20 feet away for 20 seconds.  This temporary change in focus helps relieve the visual system and can reduce symptoms such as blurred vision, eyestrain, and headaches.  

If you are affected by Computer Vision Syndrome or Digital Eye Strain, make an appointment with one of our optometrists to discuss your symptoms and determine a treatment plan.


Our eye doctor at Eye Theory in Houston, TX excels in the prescription of contact lenses, glasses and various eye diseases.  Call our optometrist at 832.831.7386 or schedule an appointment online if you would like to be evaluated computer vision syndrome or for us to help with the visual requirements of your digital screens.  Our eye doctor, Dr. Jonathan Tsao, provides the highest quality optometry services  and eye exams in Houston and Midtown Texas area.