The most common impairment of vision is caused by errors in refraction (or focus). Refraction occurs when light enters the eye through the cornea and lens. Refractive errors result when light rays do not come to a focus on the retina, causing the conditions of myopia (nearsightedness), hyperopia (farsightedness), or astigmatism.

There are three available methods to help correct refractive errors. The first two use lenses to redirect the incoming light to focus and include glasses and contact lenses. The third is an excimer laser refractive procedure such as PRK or LASIK which can reshape the cornea to better focus incoming light.

Photorefractive keratectomy (PRK) uses the excimer laser to correct nearsightedness or astigmatism by removing a small amount of tissue from the corneal surface. This reshapes the corneal surface, allowing it to better focus the image on the retina, with the goal of reducing a patient's reliance on eyeglasses or contact lenses.

With laser in situ keratomileusis (LASIK), the laser treatment is performed under a thin "flap" of the cornea. This differs from PRK in which the laser treatment is performed on the surface of the cornea after the surface epithelial cells are removed. The laser treatment procedure, itself, is the same as in PRK. Similarly, the goal of the treatment is to reduce a patient's reliance on glasses and contact lenses.

The phototherapeutic keratectomy procedure (PTK) uses the excimer laser to treat patients with corneal disorders, such as scarring, dystrophies, degenerations, and surface irregularities.


navigation bar: home page, staff directory, directions, UMDNJ web site UMDNJ web site directions staff directory
residency program /// patient care services /// research
ophthalmic medical assistant program /// continuing medical education
facilities /// faculty /// library


umdnj web site directions staff directory home page


vitrectomy refractive surgery oculoplastic surgery laser surgery cryotherapy retinopathy macular degeneration glaucoma cataract UMDNJ web site directions staff directory