The normal eye has no refractive error (nearsightedness, farsightedness or astigmatism). In its relaxed state, the eye is focused for distance vision without the need for glasses or contact lenses. This requires that the focusing power of the cornea (the curved front window of the eye) and the lens (inside the eye behind the iris) matches the length of the eye. The cornea and lens focus the rays of light from a distant object perfectly on the retina, creating a sharp image.

At younger ages, the normal eye also has the ability to focus on nearby objects by tensing the muscle around the lens and increasing its focusing power. This ability to change focus or “accommodate” for close-up vision decreases with age because the lens becomes rigid. The resulting condition is called “presbyopia,” which literally means “elder vision.” The normal eye retains good distance vision with aging, but usually begins to need reading glasses by mid-40’s.

Presbyopia is part of the aging process of the eye. It occurs in the normal eye, and can coexist with nearsightedness or farsightedness. Older people with presbyopia can often eliminate or reduce the need for reading glasses by having one eye corrected for distance and the other eye corrected for reading (keeping it slightly nearsighted). This option is called “monovision.” Monovision correction can be achieved with any of the refractive procedures we offer.