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Laser Vision Correction... Frequently Asked Questions

Reviewed by Denis M. Humphreys, O.D.

Laser vision correction is a surgical procedure for the eyes. When it comes to something this important we know you may have questions. Your eye care doctor is an important and valuable source for laser vision correction information. Your eye care doctor will help you determine which procedure will be best for you and answer any concerns you may have about the health of your eyes. With this in mind, here are some of the most frequently asked questions about Laser Vision Correction surgery:

  1. What types of vision conditions can be improved?
  2. Am I a good candidate?
  3. What procedure is best for me?
  4. Do these procedures hurt?
  5. How long does the surgery take?
  6. What is the excimer laser?
  7. What are the risks?
  8. Can I treat one eye or both eyes on the same day?
  9. How should I prepare for the surgery?
  10. What will I feel during the procedure?
  11. What is the recovery time?
  12. What if I'm not satisfied with my vision correction?
  13. Why can't lasers treat presbyopia (the need for reading glasses after the age of 40)?
  14. Is there an age cap for LASIK?
  15. Will laser surgery correct the need for bifocals?
  16. What are other sources of information?

What types of vision conditions can be improved?

A. The primary function of your eye is to focus light. You need glasses and contacts when your eye cannot properly direct light rays on the retina. The cornea, at the front of your eye, provides most of the focusing power. The lens, inside your eye, provides the fine tuning and reading ability. Light rays must focus precisely on the retina for you to see clearly. If you wear corrective lenses, you may have one of the following refractive problems:

Myopia
(Nearsightedness) occurs when your eye is too long in relation to the curvature of your cornea. With myopia, near objects are seen more clearly than distant objects.

Hyperopia
(Farsightedness) occurs when your eye is too short in relation to the curvature of your cornea. With hyperopia, distant objects are seen more clearly than near objects.

Astigmatism
occurs when your cornea is shaped like an oval. With astigmatism, more than one focal point within the eye distorts what you see.

Presbyopia
occurs when the lens hardens with age. Laser vision correction does not correct presbyopia, which usually results in the need for reading glasses in your 40's or 50's.

Am I a good candidate?

A. If you are at least 18 years old, and have good eye health with no diseases such as cataracts or glaucoma, then you are likely to be a good candidate. Laser vision correction can treat a broad range of nearsightedness, astigmatism, and farsightedness. In most cases, even patients with severe degrees of nearsightedness, astigmatism, and farsightedness can be treated. You should visit your eye care doctor to determine if you are a good candidate.

What procedure is best for me?

A. Your eye care doctor, together with your laser surgeon, will help determine the most suitable procedure for you. LASIK is the most common and accounts for about 90 percent of laser vision correction procedures.

Do these procedures hurt?

A. Discomfort will vary depending on the procedure. You will not have any discomfort or pain during the procedure itself. Less than one patient in ten has pain after the procedure, which is treated with pain medication for 24 to 48 hours. Most patients experience only some irritation, light sensitivity, and watering of their eyes for a few days. There is typically less chance of discomfort with LASIK than PRK.

How long does the surgery take?

A. Your surgery preparation process typically includes an eye examination, counseling, and the administration of mild eye drops. The entire surgical procedure usually lasts five to 10 minutes per eye. A typical procedure takes about 30 to 40 seconds of actual laser time per eye. The entire process takes approximately two to four hours.

What is the excimer laser?

A. The excimer laser is an ultraviolet laser, which utilizes argon and fluorine gases to create a cool, non-thermal beam of laser light, which can break molecular bonds in a process commonly referred to as "photoablation". The most important aspect of the excimer laser is its remarkable precision. It is able to remove 0.25 microns of tissue in a single pulse; that is, 1/200th of a human hair, 1/40th of a human cell, or 39 millionths of an inch in 12 billionths of a second.

A simple way to imagine how the laser works is to think of it as placing the curvature from your glasses or contact lenses onto the front surface of your eye, allowing you to see without corrective eyewear.

What are the risks?

A. There are some risks associated with all surgical procedures, including laser vision correction. These may include pain or discomfort, night glare, regression, scarring, under or overcorrecting and infection. Other risks include loss of best-corrected vision, which occurs in about one percent of people.

Can I treat one eye or both eyes on the same day?

A. The decision to have both eyes treated the same day depends on various factors, but is relatively common. The final determination will be made after consulting with your eye care doctor and your eye surgeon.

How should I prepare for the surgery?

A. Your eye care doctor will give you specific instructions for your individual situation, but in general you may follow these guidelines:

Soft contact lenses that are removed daily cannot be worn for at least 72 hours prior to your procedure.

Hard or gas permeable lenses are not to be worn for four to eight weeks prior to your procedure. This will allow your eye to return to its natural contour.

Food, drink, medication. You must avoid alcohol or any medication that can make you drowsy. Otherwise, there are no restrictions to eating, drinking or taking medications before your procedure. Be sure to tell your doctor about any medication you are taking.

Arrange transportation. Be sure to bring someone to drive you home, or make other arrangements for transportation.

Makeup and jewelry. Please do not wear eye makeup, perfume, cologne, hair spray or earrings.

Dress comfortably. Wear comfortable clothing that will help you feel relaxed.

Exams or paperwork. If you haven't already completed all required eye exams, signed necessary paperwork including the informed consent, and paid for your procedure, you can take care of those details when you arrive.

Last-minute questions. If you have any other questions or concerns be certain to discuss them with your doctor or laser surgeon.

What will I feel during the procedure?

A. Your doctor will place anesthetizing eye drops in your eye before the surgery, so you won't feel a thing.

What is the recovery time?

A. Many people return to work within two to four days after surgery. Speed of healing differs and those with higher prescriptions typically recover more slowly.

What if I'm not satisfied with my vision correction?

A. You should consult with your doctor to set realistic expectations concerning your surgery. However, most laser centers offer enhancement procedures at no cost to you, if needed. Ask the center about their enhancement policies because they may vary by center.

Why can't lasers treat presbyopia (the need for reading glasses after the age of 40)?

A. Presbyopia refers to the lens inside our eye not changing shape anymore to help us see up close. In refractive surgery, the laser treats the outside of the eye, not the inside.

Is there an age cap for LASIK?

A. There is no upper age limit for LASIK surgery.

Will laser surgery correct the need for bifocals?

A. No, not yet.

What are other sources of information?

A. You may want to visit the following Web sites:

You may also want to research the following books:

How to See Like a Hawk When You're Blind as a Bat, by Matthew Ehrlich, M.D.

Beyond Glasses!, by Franette Armstrong

The Eye Laser Miracle, by Andrew I. Caster, M.D.