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Category: Contact Lenses

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 Why You Should Try Multifocal Contact Lenses

Why You Should Try Multifocal Contact Lenses

Posted on by Eye Theory

Presbyopia, the inability to focus on objects up close, is a process that often begins to become more noticeable in an individual’s late thirties to mid forties. Multifocal lenses, usually being progressive lenses, are a great option that provide improved vision at various distances.

However, many also prefer to be free of glasses and look for a contact lens option. Today, there are a variety of lenses that are designed to provide the same multifocal ability as progressive or bifocal glasses lenses.

Our optometrist will find you the lens that fits your needs and eye anatomy, but it is a specific process that can take some time to fine tune. Below are some of the major components that we look for when deciding on a lens.

Your contact lens prescription

Each lens comes in a variety of powers, with the options varying between companies and product lines. After finalizing your prescription, our optometrist will make the necessary calculations and decide on the right lens for your specific needs and prescription.

In the case of high plus or minus lenses, only a few lines will have available options and the right lens will be selected for and trialled by you.

Contact lenses are chosen based on your eye’s anatomy

Each contact lens product line will come in specific sizes and curvatures. Your individual eye also has specific sizes and parameters.

It is important that our optometrist selects the correct parameters for you that allow for a good fit of the lens. A lens that is too tight or too loose can cause not only discomfort but also affect the amount of oxygen that gets to the eye.

In addition, our optometrist may also determine if you have a preference for one eye over the other. This is important because of the way some of these lenses are designed.

Select multifocal contact lenses are designed such that the center provides the correction necessary to see up close and the surrounding is for distance vision. The other eye will have the opposite correction in that the center provides proper distance vision and the surrounding area provides near vision.

Depending on your preference, our optometrist may select one eye over the other for primarily distance vision and vice versa.

Multifocal contact lenses can meet your visual needs

With the trial lens on, your vision will be assessed. It is important to keep in mind that multifocal contact lenses, while great for allowing viewing of varying distances, will often not provide vision as optimal as glasses.

There is often a compromise that must be made between the clarity of distance and near vision, as it is difficult to achieve perfect clarity at both ends. There is a happy medium that will be achieved that will allow for independence from glasses during regular daily tasks.

Depending on an individual’s visual needs, a prescription may be altered to allow for more near or distance clarity. It is common for our doctor to provide a variety of options for you to take home and test out in your daily life to see which ones work best for you.

 

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 try multifocal contact lenses.  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 Unique Glasses and Contact Lens Options

Unique Glasses and Contact Lens Options

Posted on by Eye Theory

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.

Home Blog The Basics of Keratoconus

The Basics of Keratoconus

Posted on by Eye Theory

Keratoconus is a condition that causes thinning and bulging of the clear front of the eye, the cornea. There are a variety of causative factors for keratoconus and more is being understood about its diagnosis and treatment all the time. This article will outline keratoconus, its causes, and its treatment.

What is Keratoconus?

The cornea is the front transparent surface of the eye and is largely responsible for focusing light onto the back of the eye, the retina, to allow for clear vision.

When there are deformities or changes in the curvature of the cornea, vision is therefore affected. Keratoconus is when the central cornea thins and the pressure from fluid inside the eye pushes it forward, leading to a bulging out and, if severe, a cone shape at the front of the eye.

It is a progressive disease with the highest rate of change in the teenage years and twenties with the process completing around age thirty.

The rate of progression can vary and the condition can sometimes progress later on in life as well or occur following a surgical procedure involving the cornea.

Symptoms of keratoconus include reduced vision even when corrected with glasses or contact lenses and inconsistent and highly variable prescriptions.

If the cornea is severely thinned and bulged, a break can occur where fluid from inside the eye drains into the cornea itself, leading to severe pain and visual disturbance. This acute condition, called hydrops, resolves with time and proper treatment.

What Causes Keratoconus to Occur?

Keratoconus is under constant study and causative factors are being investigated all the time. Family history and other genetics like ethnicity can play a role.

Excessive eye rubbing is an important risk factor as it increases eye pressure and strain on the cornea, leading to further degeneration.

Eye rubbing is associated with allergic or atopic conditions that cause the eyes to itch. Another possible cause can be refractive surgery, as this procedure involves altering and thinning the cornea in order to change the power of the eye.

This is why extensive testing of the cornea must be done before laser surgery to ensure that this does not occur.

Keratoconus is also associated with other genetic or connective tissue disorders, like Down syndrome and Marfan syndrome.

How is Keratoconus Treated?

In the early stages of keratoconus, it is often easily corrected with glasses or soft contact lenses. In the later stages, vision will be optimal only with the use of rigid gas permeable (RGP) lenses or scleral lenses.

RGP lenses are hard lenses that are smaller than the diameter of the colored part of the eye. These lenses will often take some time to get used to but provide excellent vision for patients.

They sit on the front surface of the eye and create a tear layer between the cornea and the lens that corrects the keratoconic irregularity and allows for better vision. Scleral lenses sit on the white part of the eye and are larger than RGP lenses.

They are also more comfortable and easier to get used to than RGP lenses. There are also hybrid lenses, which have a RGP center and soft contact lens edge, allowing for better comfort while still optimally correcting vision.

Corneal cross-linking is another treatment option for patients with keratoconus. This procedure helps to slow the progression of the cornea bulging outwards and maintains the integrity of the cornea as it is.

The procedure involves riboflavin (vitamin B2) being applied to the front surface of the eye with ultraviolet radiation exposure for 30 minutes. This makes the cornea stronger and more resilient against further change.

In severe and advanced stages of keratoconus, penetrating keratoplasty may be needed. This procedure involves transplanting a cornea from donor tissue and replacing the cornea of the patient.

Following the surgery, the patient will often be fit with a scleral lens for optimal vision.

 

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 keratoconus.  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 The Do’s and Dont’s of Contact Lenses

The Do’s and Dont’s of Contact Lenses

Posted on by Eye Theory

The use of soft contact lenses in today’s society has grown exponentially since their initial development. The amazing lens materials available and the various uses for contact lenses have contributed to their success. With the simplicity of these medical devices today, it is easy to forget the importance of maintaining the best hygiene practices for contact lens use. Below are some of the most important Do’s and Don’ts to keep in mind when taking care of your lenses and ensuring that your eyes are protected from infection.

DO Rub and Rinse

For those that are not wearing daily disposables, cleaning the lenses before going to bed is a key step in the hygiene routine. The best way to clean them is to place the lens in the middle of your palm, add some solution, and rub both sides of the lens with your middle finger. After this step, you can insert it into the peroxide or saline solution to be stored overnight. This will remove the protein and fat deposits that build up on the lens during the day

DON’T Sleep in Contact Lenses

This is often a tough one to remember for patients as it can be easy to accidentally fall asleep in the lenses. Unfortunately, this is one of the most common risk factors for infection. Overnight, the eye receives less oxygen and thus is less able to protect itself from invading microbes.

 

DO Replace Your Contact Lenses Regularly

If you are wearing monthly lenses, make sure to discard them 30 days after opening the package. Many people mistake the discard time for the number of days that the lenses are in the eyes but the best way to prevent infection is to discard the lenses according to the designated schedule. This means, for example, that even if you only wore the lenses 4 days out of the 30, you still need to discard them. Increased amounts of time outside their packaging can increase infection rates, induce more eye dryness, and cause irritation.

 

DON’T Use Tap Water

It is important to remember that contact lenses should never touch tap water. In fact, the lenses should only be in contact with specific disinfecting solutions or saline. Tap water is especially concerning as there are microbes in the water that can adhere to the lens and cause an infection. So, whether you need to rinse the lenses in order to remove debris or rewet them, make sure to never use tap water.

 

DO Clean and Replace Your Contact Lens Case

Contact lens storage cases (for monthly or biweekly lens wearers) are hot spots for bacterial growth and about 50% of cases will be contaminated. It is important to remember to clean the cases after each night of use. The best routine would be to dump out the rest of the solution, rinse the case out with contact lens solution, wipe the case and lids dry, and turn them upside down on a clean tissue. Ideally, these cases are also replaced every month or, at most, every 3 months.

DON’T Swim With Your Contact Lenses

Lakes, swimming pools and ocean water have a variety of bacteria and chemicals that can stick onto the lenses. This exposes your eyes to dangerous organisms that have the ability to damage the front surface of the eye permanently. The only time this may be done is if daily disposable contact lenses are used and are thrown away immediately upon exiting the water after a short time frame of use (i.e. 1 hour of swimming lessons).

DO Use Hydrogen Peroxide Disinfection

Monthly and biweekly lenses will need to be stored in solution overnight for up to 30 or 14 days, respectively. The best way to store them overnight and kill possible bacteria on their surfaces is in a hydrogen peroxide solution that will clean the lenses while you sleep. This solution often comes in a bottle with a red cap that is easy to identify so that it is not mistaken for a bottle of saline. This is because if hydrogen peroxide touches the eye, it will sting and burn the eye temporarily. A special case is needed to use this solution, as a disc at the bottom of the case will neutralize the solution overnight and allow the lens to be used in the morning directly from the case.

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 do’s and dont’s of contact lenses.  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 Contact Lenses for Beginners

Contact Lenses for Beginners

Posted on by Eye Theory

Considering joining the wonderful world of contact lenses? Not sure how much it will cost to start? Here is a quick guide for things to consider and costs to account for. 

 

Types of Contact Lenses Based on Replacement Frequency

The frequency in which one will need to replace the lenses is an important factor when considering which lenses to purchase. In certain cases, the optometrist may require you to select a specific replacement frequency, for the necessary purpose of promoting healthy conditions for your eyes. In the case where you may be given the option, your options will include daily, bi-weekly, or monthly replacement.

Daily contact lenses are replaced with every use. This means that each lens can only be used for one day then thrown out. The benefit of this is that daily lenses eliminate the need to store the lens in a case overnight, negating the possibility of contamination and subsequently decreasing the risk of eye infections. It eliminates the need to purchase saline solution (unless preferred to rinse off the lens if dropped). The trade-off is that more lenses will be needed and there is a higher cost to them. Though the most expensive option, daily lenses are overall the best for eye health and contact lens comfort.

Monthly contact lenses are the opposite in that a new lens is worn for one month then replaced. These lenses must be stored in a cleaned contact lens case overnight using preferably hydrogen peroxide solution. These lenses cost less but are not as easy to clean as daily lenses and the cleaning process includes a rub and rinse step. This also means that these solutions must be purchased. This adds some cost though the monthly modality is still the cheapest way to go.

Bi-weekly contact lenses are the middle option in that they are replaced every two weeks and will also require a solution for the lenses to be stored in. 

 

What to Expect at Your Contact Lens Exam

The journey to getting your first pair of contact lenses starts with an assessment with your optometrist. This will likely be a separate appointment from the annual eye exam as it requires additional time and measurements.

The optometrist will investigate which lenses are best suited for you based on various findings such as the amount of lipid in your tears, the sizes of different ocular components, the activity of choice you will be using the lenses for, and how often you plan on wearing them.

Our eye doctor may then give you some lenses to try on the same day or order some in with your correct prescription. After trying on these lenses for a week or two, the optometrist will want to see you back and make sure that the fit was comfortable and did not cause any complications on your eye.

They may also make adjustments at this exam and order a new lens. When they find that everything is acceptable, you may be good to order your 3, 6 or 12 month supply. Remember, when buying from an optometry office for 6 month or annual supplies, certain lenses may have rebates that are only available from your eye doctor.

 

Contact Lens Follow Up Care

From this point, many people forget that it is important to return to their eye care practitioner annually to ensure that there are no long term complications from the lenses (i.e. inadequate levels of oxygen to the eye, dry eye, systemic changes that affect the eye) and that the eye is still in good condition to continue contact lens wear.

This exam is also a great opportunity to check in and see if there are any new technologies in contact lenses. Recently there have been new colour contacts, transition lenses (changes to be darker in sunlight and helps with light sensitivity), and multifocal lenses for astigmatic eyes on the market. 

 

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 contact lenses.  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 Scleral Lenses: The Contact Lens You’ve Never Heard Of

Scleral Lenses: The Contact Lens You’ve Never Heard Of

Posted on by Eye Theory

Many people use soft contact lenses for their daily vision correction needs. Sometimes, however, these may not be enough to address your vision, eye health, or comfort needs with contact lenses. Other, more specialized options exist in such cases, and one of these options is the use of scleral lenses. 

 

What is a Scleral Lens? 

A scleral lens is a large diameter, rigid contact lens that vaults over the entire front clear part of the eye, the cornea, to sit comfortably on the white part of the eye: the conjunctiva and sclera. It differs from the regular soft contact lenses you may be familiar with in that it is somewhat larger, hard, and must be filled with special fluid before being placed on the eye. Even though it is made of a rigid material, it is actually quite comfortable, owing to the fact that it does not touch the sensitive cornea and constantly hydrates the front of the eye with the tear-like fluid that it is filled with. These features are the basis of why your optometrist may recommend scleral lenses to you. 

 

Uses of Scleral Lenses

One of the primary needs for a scleral lens, or any rigid lens, is to improve vision when the cornea becomes irregular and no longer transmits a clear image to the back of the eye. This can occur for several reasons: conditions such as keratoconus where the cornea thins and becomes pointed, after a surgery to the eye where the tissue is changed in some way that does not enable proper vision, or after severe injury to the cornea, again causing its structure to weaken and shape to change. If you have severe dry eye disease that is not solved by other treatments, your eye doctor may recommend scleral lenses as a way to protect the eyes from feeling dry and painful. 

 

How to Use a Scleral Contact Lens

Scleral lenses are different from other contact lenses in that they completely vault over the cornea and must therefore be filled with fluid to keep them in contact with the eye. Before the lens is put onto the eye, it must be filled to almost overflowing with unpreserved saline solution. While the wearer keeps their face parallel to the ground, the lens is raised to the eye. If it is not applied properly, a bubble will form and the lens must be removed, filled with fluid, and put on again. For removal, a plunger can be used or the eyelid can be moved underneath the lens to break suction and remove it. Like any other contact lenses that are repeatedly used, scleral lenses must be cleaned regularly by rubbing and rinsing with special cleaning solution and never with tap water. They must also be stored in disinfectant solution overnight. 

 

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 scleral lenses.  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.