University Laser Vision Center

Understanding Your Vision

Assuming that the retina, optic nerve and lens inside your eye are healthy, your vision quality depends on three elements: curvature of the cornea, power of the lens and length of the eye. These elements, when correctly proportioned and configured, allow light to focus on your retina, resulting in clear vision.

When not arranged correctly, as is the case for an estimated 120 million Americans, vision problems occur. There are four main types of vision problems caused by refractive error:

	Myopia (nearsightedness) occurs when the cornea is too steep relative to the length of the eyeball. As light enters the eye, the visual image focuses in front of the retina, resulting in a blurred or distorted view of distant images.
	Hyperopia (farsightedness) occurs when the cornea is too flat relative to the length of the eyeball. As light enters the eye, the visual image focuses behind the retina, resulting in a blurred or distorted view of close and often distant images as well.
	Astigmatism (asymmetrical or tonic cornea) occurs when an eye is shaped like a football, unlike the normal eye that has a round shape similar to a basketball. Astigmatism causes certain amounts of distortion because of the uneven bending of light rays entering the eye. Astigmatism may be present with either myopia or hyperopia.
	Presbyopia is a condition that causes many people from their 40s on to need reading glasses or bifocal lenses. It occurs when the focusing lens inside the eye becomes unable to change shape and focus on close images.

There are several ways to correct refractive error. The options include laser vision correction, glasses or contact lenses.

At University Laser Vision Center, our experienced surgeons use the state-of-the-art excimer laser to carefully reshape a thin layer of the cornea, changing its curvature and improving your ability to focus. Our surgeons are widely known for their expertise in correcting these problems, which is why many of our patients are health care professionals.

This page was last updated on: April 25, 2007.

Please call University Laser Vision Center at 410-328-5933 for more information or to schedule your free consultation.