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Home Blog Is LASIK or Refractive Surgery an Option For Me?

Is LASIK or Refractive Surgery an Option For Me?

Posted on by Eye Theory

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

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

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

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.

Home Blog Understanding Your Glasses Prescription

Understanding Your Glasses Prescription

Posted on by Eye Theory

When you receive an eye examination, you often leave with a copy of your prescription, which includes numbers for the exact specifications of the glasses you need. These numbers include the sphere, the cylinder, and the axis.

Sphere, cylinder, and axis can also all be broken down into different categories. Read on to learn about these specifications.

 

Sphere is the first number on your glasses prescription

The sphere power is the first number in the prescription and specifies the overall type and amount of power in the lens. It can be positive, indicating a hyperopic or farsighted prescription, negative, indicating a myopic or nearsighted prescription, or it can be zero.

If you have a farsighted prescription, your eyes have an easier time focusing far away and need some extra power for seeing things up close.

If you have a small to moderate number, you may have gone most of your life without needing glasses and only start requiring them when the focusing system inside your eyes begins to noticeably decrease in power (presbyopia).

For a nearsighted (ie: myopic) prescription, the eyes are naturally adapted to see at near without spectacles but require diverging power to make distant objects clear.

For low myopic prescriptions, you might only want your glasses or contact lenses to drive or see a movie, while for higher prescriptions, you pretty much need your glasses for everything you do.

 

The cylinder power is used to correct astigmatism

The second number is the magnitude of the cylinder power, which is used to correct astigmatism. It is usually specified in minus form, but can be converted to plus form by changing the entire prescription to an equivalent format.

Astigmatism is when the eye requires different powers in different orientations to see clearly, owing to its bending light like a football rather than a soccer ball: one direction with much more curvature than the other.

This can also be imagined in that someone with uncorrected astigmatism might see the vertical part of a capital letter L as perfectly clear while the lower horizontal part of it is blurry, or vice versa in any direction.

Everyone usually has a little bit of astigmatism, but some people may have none at all. Astigmatism is also not directly related to the amount of sphere power: you can have zero sphere power and a lot of cylinder power which still requires you to wear your spectacles or contact lenses.

 

The axis determines where to put the astigmatism in your glasses

The axis is the final number and is written as an angle made of three digits without the extra degree sign usually put in geometric angles.

This specifies the direction of the astigmatism correction, as it is a line that can be any degree or orientation from 180 degrees (a straight line left and right) to 90 degrees (a straight line up and down) and anywhere in between these.

The axis can be specified as with the rule (close to a flat horizontal line), against the rule (close to a straight vertical line), or oblique (somewhere in between these, close to a 45 or 135 degree angle).

As we age, we tend to move from with the rule astigmatism as children to against the rule as elderly.

 

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 your glasses prescription is made and interpreted.  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.

Home Blog Eye Problems and Down’s Syndrome

Eye Problems and Down’s Syndrome

Posted on by Eye Theory

Down’s syndrome is a condition in which chromosome 21 is duplicated, resulting in three copies rather than just two. It is associated with intellectual, developmental, and physical changes.

The eyes are one component and there are a variety of conditions that individuals diagnosed with Down syndrome may be affected by or more susceptible to. Read on to learn about some of the most common ocular findings.

 

Refractive Error and Glasses

This refers to an individual’s prescription in corrective eyewear such as glasses or contact lenses in order to see as clearly as possible. Patients with Down syndrome are more likely to need corrective eyewear whether for nearsightedness, farsightedness, or astigmatism.

 

Strabismus is a Common Feature in Down Syndrome

Strabismus refers to an eye turn that the individual may have. This could be one eye turning in and out, or both eyes turning and switching back and forth. It could also be present at all times or only at some points in the day and associated with certain activities.

An eye more often turns inward, but in either case amblyopia or lazy eye may develop. This means that because the turned eye is not being used as frequently, it will not receive as much visual stimuli and its pathways to the brain will not fully develop, leading to permanent vision reduction in that eye if the eye turn is not fixed in childhood.

 

Down’s Syndrome Can Cause Keratoconus

At the very front of the eye is the clear cornea, which is thinned in this condition, causing the fluid from inside the eye to push outwards. This causes the cornea to bulge outwards into a cone shape and distorts the curvature, affecting vision. This condition has been shown to be associated with eye rubbing and our optometrist will check to make sure that there are no underlying causes inducing this.

Cataracts

A cataract refers to the clouding of the lens within the eye, causing blurry vision or a spot in vision. If noted, our optometrist will assess to see how severe the cataract is and, if needed, refer the patient to receive surgical treatment to replace the lens. Patients with Down syndrome are at higher risk for either congenital cataracts (present at birth) or developing cataracts as they age earlier than the general population.

Glaucoma

This is a group of disorders that refer to the death of the nerve cells at the back of the eye, which are responsible for providing peripheral vision. This is often associated with higher eye pressure but this is not the only variable.

Treatment includes eye drops, instilled everyday, to lower eye pressure or certain laser procedures that help with outflow of the fluid within the eye to lower the pressure. Individuals with Down syndrome are at higher risk for higher eye pressures and glaucoma.

Blepharitis

This is a condition that leads to inflammation of the eyelids and the glands within them. It is often associated with a dry or burning feeling in the eyes and redness. Eyelid hygiene is an important component for this condition and it can be treated with eyelid cleaning, warm compresses, steroids, or antibiotics.

 

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 Down’s syndrome can affect the eyes.  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.

Home Blog How Pregnancy Can Affect Your Eyes

How Pregnancy Can Affect Your Eyes

Posted on by Eye Theory

In addition to the many other bodily changes taking place during pregnancy, a mom-to-be can also have changes in the eyes. These are usually transient and go back to normal after the pregnancy, but it is wise to keep a close watch on them with an eye examination if changes to vision are occurring. This article will outline some of these possible changes.

Your Glasses Prescription May Change When Pregnant

It is common for the mother to experience blurry vision due to a change in her refractive error, which can also be understood as a change in her degree of nearsightedness, farsightedness, or astigmatism as measured in her glasses prescription.

This is due to increased fluid retention throughout the body during pregnancy, including within the eye. One location for this is within the cornea, the clear front surface of the eye, causing a change in its thickness and curvature. It can also occur in the natural lens within the eye as well.

This would in turn alter the prescription needed to allow one to see clearly. This change is temporary and will likely return to normal after delivery.

It is common that our optometrist will wait six to nine weeks after delivery to update your prescription for glasses or contact lenses.

 

Gestational Diabetes Can Occur During Pregnancy

During pregnancy, women can develop gestational diabetes, defined as an increase of glucose in the blood during pregnancy that usually resolves after delivery.

Diabetes on its own can have detrimental effects to the health of the eyes in addition to the rest of the body if it is not well controlled for long periods of time.

Gestational diabetes usually does not get bad enough to cause these changes or symptoms, but it may exacerbate pre-existing diabetes by making blood sugar more difficult to control and regulate.

Other risk factors for diabetic retinopathy include coexisting hypertension, preeclampsia, greater severity and duration of diabetes, etc.

If you have an eye examination during your pregnancy, our eye doctor will find anything out of the ordinary if it is present and manage it accordingly or inform your other doctors of the changes.

Dry Eyes May Also Worsen

As mentioned previously, fluid can accumulate in the cornea during pregnancy, causing a decrease in sensitivity at the front of the eye.

The eyes are thus less responsive to debris or dryness in the eyes, exacerbating the effects of dry eyes due to a lack of activation of the body’s defense responses like tearing.

In addition, pregnancy and its associated hormonal changes disrupt the cells that are responsible for creating the watery fluid that makes up the tear layer.

This is key as it helps keep the eye moisturized, nourished, and healthy overall. Common symptoms of dry eye disease include a gritty, burning feeling and are often transient as well.

Mild dry eyes experienced during pregnancy can be managed with interventions like artificial tears and hot compresses, but there is a lot that can be done if the signs and symptoms are more intense and pose a risk of eye damage. 

Contact lens intolerance may also be experienced, secondary to symptoms associated with dry eye disease. For this reason, it is common to wait six to nine weeks after delivery to get fitted for contact lenses again.

 

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 more ways pregnancy can affect your eyes.  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.

Home Blog Do You Have a Strong Glasses Prescription?

Do You Have a Strong Glasses Prescription?

Posted on by merrym

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.

Home Blog Choosing the Right Lens Options for Your New Glasses

Choosing the Right Lens Options for Your New Glasses

Posted on by Eye Theory

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.

 

Home Blog Presbyopia and Vision Changes As You Age

Presbyopia and Vision Changes As You Age

Posted on by Eye Theory

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.

Home Blog Glasses and Refractive Error

Glasses and Refractive Error

Posted on by Eye Theory

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. 

 

Astigmatism

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.