Terminology and Definitions

The Normal Eye

In the normal eye, light enters and is bent or refracted by the clear, strong tissue at the front of the eye called the cornea. The cornea, along with the crystalline lens, focuses incoming light onto the retina at the back of the eye.

Myopia (The Nearsighted Eye)

Myopia is the most common refractive condition, affecting one in four people in North America. Myopic patients are near-sighted: they see near objects more clearly, but distant objects are blurry or even indistinguishable. Myopia occurs when light rays entering the eye are focused in front of the retina instead of directly on it. Traditionally, your eye care professional prescribes glasses or contact lenses to correct the condition.

Hyperopia (The Farsighted Eye)

Hyperopia is caused when light rays are not converged or focused by the time they reach the retina. The eyeball is actually too short in relation to its focusing elements, and the cornea maybe flatter than normal. Hyperopic patients are farsighted: they can focus on more distant objects, but not images that are close at hand. Younger people may be farsighted, but unaware of it because they have enough flexibility in their focusing power to compensate.

Astigmatism

Astigmatism may coexist with either myopia or hyperopia. In the astigmatic eye, the front of the cornea is not equally curved; it is slightly oval (somewhat like a football) in shape. Light rays that enter the eye are unequally bent and what results is a distortion of the image. In an eye with astigmatism, the refractive elements do not focus light to a point. Astigmatism is relatively common. The laser is so precise; it can remove a single layer of cells without affecting neighboring cells.

Presbyopia

Presbyopia occurs when the eye's focusing system weakens and is no longer strong enough to allow one to see comfortably at close distances; vision correction is then required with the aid of reading glasses or bifocals. Presbyopia is not currently an available laser vision correction treatment.

PRK

Photorefractive Keratectomy (PRK) involves the removal of less than ten percent of the corneal tissue. The laser is so precise; it can remove a single layer of cells without effecting neighboring cells. The Nidek Technology excimer laser system emits a rapid succession of laser pulses. With each pulse, the beam spot widens removing microscopic layers from the surface of the cornea. The end result is a re-sculpting of the cornea, which allows light to properly focus on the retina.

BLADE FREE LASIK

Laser-assisted in-situ Keratomileusis (LASIK), is now ALL LASER LASIK. The skilled surgeon uses the latest technology in creating a corneal flap with an IntraLase® FS laser light. Blade free LASIK is a highly sophisticated way of making a flap with rapid pulses of the cool IntraLase® Laser light. As the laser moves back and forth across your eye, a uniform layer of tiny microscopic bubbles form just below the corneal surface at a specific depth and position determined by the surgeon. The corneal flap is created by gently separating the tissue where these bubbles have formed. The flap is folded back so the surgeon can correct your vision by reshaping the cornea using the Nidek® excimer laser. Next, the laser is applied to re-sculpt the internal corneal tissue. The Nidek® laser is so precise; it can remove a single layer of cells without affecting neighboring cells. The Nidek Technology® excimer laser system emits a rapid succession of laser pulses. With each pulse, the beam spot widens, removing microscopic layers from the surface of the cornea. The end result is a re-sculpting of the cornea, which allows light to properly focus on the retina. The flap is then repositioned back over the cornea.