Nearsighted (Myopia)

More than 70 million people in North America are nearsighted. Myopia is the medical term for nearsightedness. Myopia occurs when an eye is too long for the cornea's curvature. Light rays entering the eye do not come to a sharp focus on the retina at the back of the eye. Instead, they focus further forward, producing a blurred image.

The term "nearsighted" means that you can see "near" objects clearly without your glasses, but objects further in the distance are blurry. There are varying degrees of myopia or nearsightedness. The more myopic you are, the more blurred objects appear in the distance, the higher your eyeglass prescription and the thicker your glasses. Of all myopic people, about 90% have corrections less than -6.00 diopters.

The table below shows the categories of severity for myopia:

Almost everyone feels that their myopia is severe, because of how dramatically dependent they are on glasses and contact lenses. However, only one in ten myopic people are actually in the severe and extreme categories.

Farsighted (Hyperopia)

Hyperopia is the medical term for "farsightedness." It occurs when an eye is too short for the cornea's curvature. Light rays entering the eye focus behind the retina, and as a result a blurred image is produced. Farsighted individuals, however, can use their focusing muscles to "pull" the image forward onto the retina. In a young person with severe hyperopia, or once presbyopia sets in around age 45, distant objects are seen more clearly than near objects. Certain laser technologies, such as holmium lasers and hyperopic LASIK correct this condition.

Bifocal Wearers (Presbyopia Treatment)

Presbyopia is the normal process of aging, where the natural lens of the eye loses some of the flexibility that characterizes a younger eye. This usually occurs at age 40-50. Everyone experiences presbyopia, some sooner, some later. Because of this normal process, nearsighted people begin to wear bifocals in their forties, and those who never needed glasses before may require reading glasses. The one advantage to mild myopia is the ability to remove your glasses after age 40 and continue to read (your myopia effectively counteracts your presbyopia). After having the excimer laser lasik procedure, you will lose this ability. You will typically be normally sighted after the procedure, and you will need reading glasses for small print, like every other normally sighted person at age 40-50. The excimer laser has no effect on your focusing muscles. Patients who are experiencing the effects of presbyopia cannot be helped by the excimer laser, however, there are new techniques being developed for this condition.

Astigmatism

Astigmatism is derived from the Greek word "stigma" which means point. In astigmatism, light is not brought into a sharp point of focus. Rather, the light is more diffused and the image is therefore not clearly seen. By eliminating or reducing the corneal irregularity, the laser can eliminate or reduce astigmatism while treating other refractive errors.