Skip to main menu Skip to main content Skip to footer

LASIK / Types of LASIK

Types of Laser Vision Correction

Laser vision correction changes the sharpness of the vision by using a cold laser to microscopically alter the outer curvature of the eye. With our advanced technology, the entire treatment takes less than five minutes and is painless. We perform all three of the major versions of laser vision correction:

Happy man in casual clothes

LASIK

The most common version of laser vision correction is LASIK, which has been performed in the United States since 1996. Dr. Caster was one of the twenty doctors in the United States who performed LASIK treatments as part of the original FDA approval process of LASIK. LASIK is a two-step process. The first step is the creation of a flap, which enables us to apply the second step, the laser reshaping of the eye, below the outer surface. By applying the treatment below the surface, we allow the eye to heal very quickly without any significant discomfort. We perform the LASIK version in the majority of our patients.

 

All-Laser LASIK Advantages and Disadvantages

Advantages

  • LASIK offers an extremely rapid return of excellent vision. Most patients are able to drive and return to work the very next day.
  • There is no pain during the LASIK procedure using our newest LASIK technology. For the first 4 hours after the procedure, there will be some scratchiness, but no pain!
  • The LASIK procedure is very quick. There are two steps, each requiring 15 seconds of laser treatment.
  • Extremely long track record — LASIK treatments have been performed by Dr. Caster since 1996.

Disadvantages

  • You need to be careful, especially during the first week, to not rub your eyes. Googles are recommended while you sleep during the first week, to help with this. Rubbing your eyes the wrong way during the early healing period can require an adjustment treatment.

 

PRK

Also known as LASEK or Advanced Surface Treatment. PRK is preferable for some of our patients, especially those with moderate dry eyes, thin corneas, irregularly shaped corneas, or certain hobbies such as boxing. PRK is the least invasive version of Laser Vision Correction and has been performed by Dr. Caster since 1996. In PRK, the laser reshaping of the vision is performed near the surface of the eye, rather than deeper within the eye as in LASIK or SMILE LASIK.

Because PRK is performed near the surface of the eye, there is typically one day of pain, which is treated with numbing eye drops applied at home. Although most PRK patients are driving and back to work the next day, the vision recovery is slower than with the other laser techniques.

 

PRK Advantages and Disadvantages

Advantages

  • PRK is the least invasive method of laser vision correction. The treatment is performed on the surface of the eye. There is no flap made during PRK. For people concerned about the flap creation, this is very comforting.
  • With PRK we can treat higher levels of nearsightedness/astigmatism, as well as thinner or irregularly shaped corneas, than with LASIK or SMILE.
  • Patients with drier eyes are best treated with PRK.
  • Trauma to the eye is not an issue. Martial arts enthusiasts, soccer players, and some other athletes prefer PRK for this reason.
  • Extremely long track record — Dr. Caster has been performing PRK since 1996.

Disadvantages

  • You are required to wear a special contact lens. We put this contact lens in at the conclusion of your treatment and take it out 5-7 days later.
  • There is typically one day of pain after PRK, which is treated with numbing eye drops at home as needed.
  • The return to excellent vision is much slower than with All-Laser LASIK or SMILE. The vision will be usable but not extremely sharp for weeks to months.

“My prescription was -10 with my astigmatism included. I love it! It’s a different world!”

Chimdi Ihezie

SMILE LASIK

SMILE LASIK, also known as ReLex SMILE, is the newest version of laser vision correction. SMILE, which stands for Small Incision Lenticule Extraction, consists of one painless laser step lasting less than 30 seconds. As with all types of laser vision correction, you are able to get up from the treatment and see an immediate improvement, though final vision (as with all types of laser vision correction) takes about three months. Over 5 million SMILE treatments have been performed world-wide.

SMILE LASIK is performed with the VisuMax laser, created by Zeiss. The VisuMax laser technology is truly amazing. The laser creates 500,000 tiny spots every second. These spots are placed very close to each other and free up a thin layer (similar to a contact lens) within the center of the cornea. The laser also creates a small tunnel connecting the thin layer to the outside of the eye. The doctor then reaches in through the tunnel, frees up the thin lens, and pulls it out. Removal of this thin lens changes the curvature of the eye, correcting the focus of the vision.

SMILE LASIK can only be achieved with the VisuMax laser by Zeiss. Only this laser has the necessary precision to perform this procedure. At the Caster Eye Center, we use the VisuMax laser not only to perform SMILE, but also to perform the first step of the all-laser LASIK procedure. Because this laser places so little pressure on the eye, treatment with this laser is pain-free. (For our engineer types, the VisuMax laser is the only femtosecond laser that is opto-electronic; all other femtosecond lasers are opto-mechanical in design.)

 

SMILE Advantages and Disadvantages

Advantages

  • There is no flap with SMILE LASIK. The treatment is performed completely within the interior of the cornea, so there is no flap at all. Patients do not have to worry about a flap that can be moved or disturbed in the future. You do not need to use goggles to protect your eyes during the initial few days after this procedure.
  • There is a little less short-term dryness with SMILE LASIK. Because there is no flap, fewer of the corneal nerves are affected, leading to less short-term dryness. You therefore need to use less moisturizing drops during the initial healing after the procedure.
  • Long track record — SMILE treatments have been performed by Dr. Caster since 2016. Over 7 million SMILE treatments have been performed world-wide.

Disadvantages

  • Enhancement (fine-tuning procedure) of SMILE, which is required about 4% of the time,  cannot be done using SMILE, but must be performed with LASIK or PRK.

FAQ about SMILE LASIK

SMILE is shorthand for “Small Incision Lenticular Extraction”. ReLex is shorthand for “Refractive Lenticular Extraction”. Both of these names refer to the small lens, or lenticule, which is removed from the central part of the cornea.

No. Only certain prescriptions are suitable for SMILE. Dr. Caster will determine and discuss your suitability during your personal consultation with him.

The vision results are equivalent to the results obtained with all-laser, wavefront LASIK.

Patients walk out of the laser room immediately after SMILE and most are able to drive and go to work the very next day.

This is a pain-free procedure.

Which Laser Treatment is Best for Me?

The most popular variation of laser treatment is called LASIK. Other names include IntraLasik, Femto-LASIK, and all-laser LASIK. In this technique, the laser treatment is made within the cornea, rather than near the corneal surface. This is accomplished by using a laser to create a protective flap in the front 20% of the cornea and then applying laser treatment to the tissue beneath the flap.

The vision correction treatment can also be applied near the surface of the cornea (instead of under a protective flap), in which case the technique is referred to as Advanced Surface Treatment. This technique has several minor variations, which include PRK (for “photo-refractive keratectomy”), Lasek, and Epi-LASIK. In PRK, the thin layer of soft tissue coating the outside of the eye (the epithelium) is removed and the laser energy is applied to the firm tissue underneath. In Lasek–with an “e”–the soft tissue on the surface is replaced after the laser treatment. In Epi-LASIK, this thin layer of soft material is folded back using a machine. PRK, Lasek, and Epi-LASIK are very similar to each other. When the laser treatment is applied to the tissue deep within the cornea (as in LASIK) instead of near the surface (as in Advanced Surface Treatment), the healing is quicker with more rapid vision recovery.

SMILE LASIK is “small incision” laser correction. A laser is used to create a thin, lens-like layer within the cornea, as well as a narrow tunnel to the surface. The doctor reaches in to separate and remove the lens through the tiny tunnel.

The final visual results are the same with each of the versions of laser vision correction. The technique that is best for you depends on your very particular eye measurements, lifestyle, and visual needs. You will be able to discuss this and any other questions that you have when you meet with Dr. Caster during your personal consultation.

Results

The vast majority of patients no longer need glasses or contact lenses for distance vision after laser vision correction. Almost all patients who have laser vision correction see better without glasses after the procedure, frequently better without glasses or contacts than they did before the treatment with glasses or contact lenses. After the initial treatment,  96% of the patients achieve 20/20 or better vision without glasses, with 99% of the patients achieving 20/25 or better vision. For patients with mild nearsightedness, farsightedness, or astigmatism, the results are better. Patients requiring higher amounts of correction will have less accurate results. The general rule is: more accurate results will be obtained in people who require less treatment.

Clicking on the Laser Vision Correction Enhancements column takes us to the wrong place!

If needed, the results can be further improved through a repeat laser treatment. There is no additional fee to have a “touch-up” procedure within the intial 18 months. We perform enhancement treatments in 4% of our patients.

These results are very impressive, but it is impossible to tell you exactly what your results will be as every individuals’ case differs. No guarantees can be made about the outcome of laser vision correction surgery in any individual case, because each person responds in a slightly different way. If you will only be satisfied with “perfect” 20/20 vision without glasses after laser treatment, then please do not have the surgery. Avoid any doctor or clinic that promises you a specific result, because that simply is not possible. At Caster Eye Center, we have a dedicated and knowledgeable staff that can provide you all the information you need before your vision correction procedure.

The quality of your vision after laser vision treatment at our Beverly Hills office is usually superior to vision with contact lenses or glasses. Patients generally have less glare than they had with contact lenses, and of course the inconvenience and discomfort of contact lenses is eliminated. Side vision isn’t blocked, as it is with glasses, and there is no longer the problem of dirty, wet or scratched glasses.

Safety

There are three common complications that we like to emphasize with our patients. Of course, other problems are possible, but these are by far the most common issues:

Need for enhancement

LASIK, SMILE, and PRK are not one hundred percent accurate one hundred percent of the time. We get patients very close to perfect almost all of the time, but in around 4% of the treatments we are close to but not perfect. Most of these people can see very well and are not using any glasses or contact lenses for distance vision, but if we can make the vision even a little sharper, that is our goal. In these situations, we like to wait 3-6 months to be sure that we have the final results, and then perform an enhancement treatment. We do not charge any additional fee for this enhancement treatment, as long as it is performed in the first 18 months. If we can make the vision any better, we will offer a touch up. We will do everything possible to enable you to see as well as you are capable of seeing.

Dryness

Increased dryness on a temporary basis is very common after LASIK. Permanently increased dryness is rare. Dryness after treatment is more common in people who have a lot of dryness before treatment, and will often last up to three months. For people who have extreme dryness prior to treatment, we often recommend the PRK version of treatment.

When wearing contact lenses, many people experience dryness compared to wearing glasses. But after LASIK you will not be wearing contact lenses anymore. Your dryness following LASIK (after the initial healing period) will be similar for most people to eye dryness with glasses, which is typically less than the dryness with contact lenses. Freedom from the dryness and irritation of contact lenses is a major benefit of LASIK.

There are many treatments for the temporary dryness following LASIK treatment. The most effective seems to be taking fish oil liquid or pills (or flax seed oil for vegetarians). The omega-3 fatty acids in fish oil makes the tears much more effective and greatly reduces symptoms of dryness.

Halos and night vision symptoms

Night vision issues are not much of a problem anymore since we began using the Allegretto laser. However, this still remains a problem with other lasers (that we do not use), so we like to discuss it.

All people, whether or not they have LASIK, have some degree of halos at night. To prove this to yourself, go out and look at the full moon at night, and you will notice that there is softness to the edge of the moon. We call this a halo. When you view the full moon during the daylight, this softness is not present. In the past, and with other lasers, the halos were made worse in around 25% percent of patients. Although this almost never interfered with the ability to drive or live your life, it was annoying for some people.

With the Allegretto laser, there is commonly a short-term increase in the night halos, lasting for a few days or weeks, sometimes up to several months.  However, on a permanent basis, the Allegretto laser is the only laser in which the average patient typically experiences less halos than with glasses or contact lenses. This is one of the major advantages of the Wavelight Allegretto laser over all other lasers being used today.

Laser Vision Correction Enhancements

Sometimes, about 4% of the time, the LASIK correction is very close to but not perfect. Why does this happen? Because we are dealing with living tissue which can heal slightly differently in different people. In these cases, we can improve the vision further with a second treatment, called an enhancement or touch-up. We usually wait at least three months after LASIK and six months after PRK before performing an enhancement treatment and most patients are seeing well-enough while waiting for their enhancement that they do not need glasses or contacts. The enhancements are generally quicker and even easier than the first treatment.

Also, some people will have a change in vision years later. We expect a change in the near vision as a person reaches 45 years of age, and we can perform a second treatment to adjust for the near vision with monovision if that is desired by the patient. Some will want monovision, with one eye adjusted for near vision, while others want to keep both eyes optimally for distance.

If the distance vision changes as you age, (remember, LASIK will not stop naturally occurring aging changes), a fine-tuning enhancement can be performed even many years after your original treatment. We estimate this will be desired in about 5% of people.

There is no fee for any enhancements performed during the first 18 months after the original treatment. If changes occur later on and enhancement is desired, there is a fee, though special arrangements can be made regarding this.

LASIK after RK

RK (radial keratotomy) was a popular form of vision correction before 1995. With radial keratotomy, multiple incisions were made in the cornea to correct nearsightedness with or without astigmatism. No laser was used in RK treatment. Although the RK treatment eliminated the need for glasses or contacts, it was not as accurate nor as easy as our current laser treatments.

People with previous RK will sometimes experience a change in their vision as they age, with the new development of farsightedness, nearsightedness, or astigmatism. This new vision problem can be corrected with laser vision correction, using either the LASIK or the PRK technique.

Dr. Caster has corrected the vision of many hundreds of people with previous RK. The treatment laser must be programmed in a slightly different fashion to obtain the ideal correction, but with this modification, the results of laser vision correction in people with previous RK are very positive.

LASIK and Cataracts

Cataracts are a clouding of the lens inside the eye, resulting in a clouding of the vision. Cataracts are not caused by laser vision correction, nor are they treated with laser vision correction. Cataracts also cannot be treated with glasses or contact lenses. If the cataracts are mild and are not affecting the vision to any significant degree, then no treatment is required. If the cataracts are significantly negatively impacting the vision, then the treatment is to remove the cloudy lens from within the eye (cataract extraction) and replace it with a new artificial lens (lens implant). Sometimes after cataract removal, glasses are still needed for ideal distance vision. In these situations, laser vision correction can be easily performed to improve the distance vision and eliminate the need for glasses for distance vision. Of course, if the vision is hampered by other problems, such as macular degeneration, then laser vision correction will not be helpful.

How long does LASIK last?

LASIK by Age

Teens and Young Adults (18-25 years old)

As you grow, the eyes grow, too. At some point, the eyes stop growing and you reach your final level of poor vision. For many people, ocular maturity happens by age 16. For most, the vision is stable by age 18, but for some the final vision is not reached until age 25.

LASIK is best performed when your eyes have stopped changing, which is a different age for each person. If your eyes are changing only a little that will not matter, but if your eyes change a great deal after LASIK, because you are still growing, then you might want to have a second treatment later on. So we like to see only a very mild level of change in nearsightedness for a two-year period for people in this age range prior to treatment.

Adults 25-45

This is the age when your personal life and your career are expanding. The glasses and contact lenses can be irritating and hold you back in many ways, and LASIK can be very liberating. We hear from so many people that the two best days in their lives are when they had LASIK and when their first child was born! That is an incredibly strong endorsement.

Almost all people in this age group have very stable vision, which means further LASIK will probably not be needed. And the problems of reading glasses have probably not yet surfaced.

Adults 45-65

Many people have enjoyed great distance vision up to this age, and then begin to lose the close-up vision. Others first begin to lose the close-up vision in their forties and then begin to lose the distance vision as well. Others have had good distance vision using glasses or contacts, but now have trouble with close-up vision as well.

Around age 45 the problem of reading glasses typically begins. People who have always had great close-up vision, even when wearing their distance glasses or contact lenses, begin to experience some blurriness with their close-up reading vision. This vision problem is different from the vision problems that occur earlier in life, and is due to the lens deep within the eye becoming stiffer and losing its ability to change focus from far to near. This is known as presbyopia, which is the farsightedness of middle age.

Adults in the age range have a choice of correcting both eyes for distance and then using drugstore reading glasses to help with fine close-up vision. This is what a lot of people in this age group do with their contact lenses and what we can do with LASIK. Alternatively, many people use contact lenses with monovision, in which one eye is optimized for distance correction and the other is optimized for close-up. If a person enjoys vision with monovision, we can use LASIK to correct the vision this way.

Many people in this age group have never thought of monovison. Although it sounds very strange, it is surprising how many people love monovision and the more complete freedom from glasses that monovision provides. Easy-to-perform testing in our office will show you what monovision is like and you can determine whether or not it is right for you.

Adults 65 and older

We are all as young or as old as our attitudes. Thanks to medical advances, glasses and contacts are not necessary at this age. There is no upper age limit for LASIK.

If we live long enough, almost all of us will develop a cataract, which is a cloudiness of the lens deep inside the eye impairing vision. If significant cataracts are present, then a cataract removal is preferable to having LASIK. However, if cataracts are not very advanced, are not impacting vision, and have not been progressing, then LASIK is an option. Also, if glasses are still necessary after cataract removal, then LASIK can be performed to improve the vision without glasses.

LASIK and the Military

One of the most powerful “weapons” in the United States military is laser vision correction. LASIK is widely used in all branches of the military, significantly improving the fighting ability of our troops.

The military has now performed over 600,000 laser vision correction procedures on United States military personnel. The Department of Defense carefully monitors the results of all of their laser vision treatments, and they have found that laser vision correction is highly safe and highly effective. Some interesting results of the many clinical trials conducted by the Department of Defense include:

Extensive research by the Department of Defense has repeatedly proven the extremely high level of safety and effectiveness of laser vision correction. This research has shown that patients with laser vision correction are suitable for the most visually demanding tasks in the world, in both daylight and in darkness, as well as extremely dry, wet, or dusty environments.

Troops who are treated with LASIK or PRK no longer need to worry about dirty, sweat-covered glasses, dry and irritating contact lenses, or losing their glasses or contact lenses during life-threatening combat. This applies to troops on the ground, in submarines, or aviators who fly very fast and expensive fighter jets. “Landing a jet on an aircraft carrier in the middle of the ocean at night requires amazing vision. My vision was good with contacts, but it is amazing after LASIK by Dr. Caster.”

The military provides LASIK and PRK to active service members, but there is a long waiting list. We continue to treat many men and women who are members of the United States military, and we are proud to help each one perform his or her job more effectively and safer, as well as help each service member better enjoy life free of glasses and contact lenses. Fabulous eyesight, which is so important to a high quality of life in so many ways, is critical to all aspects of the military. As one Army sergeant explains, “After LASIK, our vision is always ready for combat. No worries about dirty glasses or watery contact lenses.”