Until recently, if you were one of the millions of people living with a refractive error, eyeglasses and contact lenses were the only options for correcting vision. Now laser surgery has become a popular choice.
An acronym for Light Amplification by Stimulated Emission of Radiation, lasers have been utilized to perform eye surgery since the early 70s. Lasers are precise, allowing energy to permeate the target tissue, without disturbing surrounding tissue.
What causes a refractive error?
Refractive errors occur as a result of an irregularly shaped cornea, or a very short or a very long eyeball. The cornea is the clear, dome-shaped surface that covers the front of the eye. The cornea helps protect the eye from dust, germs and other harmful matter. As the outermost layer, it also aids in controlling and focusing light into the eye. The curvature of the cornea determines its power and its capacity to control and focus light as it enters the ocular system. If this system is perfectly formed, the cornea is the correct curvature to bend, or refract, light images accurately onto the retina. However, when the cornea has an irregular shape or the power (curvature) is not exactly correct for the length of the eye, it will not precisely refract light onto the retina, thus affecting vision.
Types of refractive errors
- Myopia (Near-sightedness) – Objects that are distant appear blurry while reading vision and close objects are clear. The cornea has too steep a curve for a normal length eye, or the eye is too long for a cornea with an average amount of curvature.
- Hyperopia (Far-sightedness) – In this case the opposite is true. Far away objects appear clear while near objects appear blurry because the corneal curvature is too flat or the eye is too short.
- Astigmatism – The shape of the cornea is similar to the back of a spoon or the side of a football. That means the corneal curvatures are not equal, but instead more curved in one direction and flatter in another. This will distort the appearance of objects that are close and distant.
What laser can be used to treat refractive errors?
The Excimer laser is a cool laser used to treat refractive errors by permanently reshaping the cornea.
What laser procedures are available at Eye Institute of Marin?
Dr. Najafi-Tagol offers LASIK and Photorefractive Keratectomy (PRK). During these procedures, the cornea is reshaped to improve focusing power. Possible side effects of both surgeries include undercorrection and overcorrection.
If you would like to schedule an evaluation with our experienced, board certified eye physician and surgeon Dr. Kathryn Najafi-Tagol, call Eye Institute of Marin, conveniently located in San Francisco Bay at 415-444-0300.