How Eyes Work : Similar to a camera, the eye works by focusing light as it hits the eye. Light entering the eye first passes through a transparent layer called the cornea.
The cornea is the lens of the eye and focuses the light. Behind the cornea is another lens called the crystalline lens which further focuses the light. After the light has been focused it makes a clear image on the retina at the back of the eye. Lastly, this image(s) are then transmitted to the brain by optic nerves. Vision problems usually come form the eyes inability to focus the incoming light so the retina can receive a clear image.
Cross section of eye with crystalline lens behind cornea
Home
Lasik Procedure
Lasik or PRK
Lasik Problems
Choose Lasik Doctor
Common Lasik Questions
Common Vision Problems
How Do Eyes Work
Lasik Terms
Lasik News
Below is a list of some of the main vision problems:
1) Nearsightedness - Nearsighted people see near objects better than those farther away. Nearsightedness is also known as myopia. What happens with nearsighted vision is light rays from distant objects are focused not onto the retina but in front of the retina. Nearsightedness occurs when the cornea and the crystalline lens together have too much focusing power for the length of the eye.
2) Farsightedness - Farsighted people see far off objects better than those that are close. Farsightedness also known as hyperopia happens when the cornea and the crystalline lens together don't have enough focusing power for the length of the eye. light rays form distant objects are focused not onto the retina but behind the retina.
3) Astigmatism - Astigmatism occurs when a persons eye focuses light rays unevenly. Astigmatism happens when the cornea has a irregular shape. People with astigmatism see things both far and near out of focus.
4) Presbyopia - presbyopia happens when a persons eyes gradually loose the ability to adjust the focus. This typically occurs between the age of 40-50 as the eyes begin to age.
Resources Contact About Lasik Facts