LASIK can be used to correct myopia (nearsightedness), hyperopia (farsightedness) and astigmatism.
In a “normal” eye, light from a distant object is focused precisely on the retina, making the object appear clear and distinct.
In the normal eye, the cornea is the “clear window” on the front part of the eye. More than two-thirds of the refractive power of the eye is in the cornea. The retina is the inner lining of the back part of the eye that converts light into electrical signals which are then interpreted by the brain.
Correction of Myopia (Nearsightedness) with LASIK With myopia, light from a distant object focuses in front of the retina, making the object appear blurred.
Myopia is a relatively common condition in which distant objects appear blurred while near objects can be seen clearly. Myopia is caused by an eye that is “too long”, or a cornea that has too steep of a curvature in relation to the length of the eye.
Myopia is corrected by making the central cornea flatter, thereby refocusing the light on the retina as in a “normal” eye.
Correction of Hyperopia (Farsightedness) with LASIK With hyperopia, light focuses behind the retina, making near objects appear more blurred than distant objects.
Hyperopia is caused by the eye being “too short”, or a cornea that has too flat of a curvature in relation to the length of the eye. Although the primary problem is near vision being blurred, distant objects can also appear blurry depending on the degree of hyperopia and the age of the individual.
Hyperopia is corrected by making the central cornea steeper, thereby refocusing the light on the retina as in a “normal” eye.
Hyperopia should not be confused with presbyopia, which is poor near vision due to the normal aging process in the crystalline lens of the eye. A comprehensive eye exam can determine whether poor near vision is due to hyperopia, presbyopia, astigmatism, a combination of these refractive errors, or an eye health problem.
Correction of Astigmatism with LASIK With astigmatism, light focuses in two distinct places in the back of the eye, distorting both distance and near vision. It is caused by the cornea or the lens having a non-spherical shape.
Unlike older generation lasers, the VISX excimer laser used by the surgeons at Caplan Eye Clinic has the ability to correct astigmatism at the same time as the myopia is being treated by making the cornea “more spherical”.
