How You see
The eye functions like a camera. Light rays enter the eye through the cornea (the clear front window), pass through the pupil (the hole in the center of the iris), and then through the lens, finally reaching the retina (the film) at the back of the eye.
When light rays land on the retina, they form an upside-down image. The retina converts the image into impulses that travel through the optic nerve to the brain, which converts them into upright visual images.
Vision is clear only if the cornea and lens correctly bend or "refract" the light rays and focus them on the retina. Blurry vision may be due to what is called a "refractive error" --- the failure of the cornea and lens to focus light properly.
Prescription eye glasses, contact lenses, and refractive surgery correct or improve refractive errors by focusing light rays closer to, or directly onto, the retina.
More than 90 percent of our knowledge is obtained through our eyes making vision the most valued of the five senses. However, millions of people suffer from diseases, disorders or injuries to the eye.
Regular eye examinations should provide the basis for maintaining proper eye health as many eye diseases and disorders have no symptoms or early warning signs. However problems or injuries can occur suddenly and unexpectedly.
Almost all eye injuries can be prevented. Many sports and recreational activities, including tennis, baseball, basketball and racquetball, carry some risk of eye injury. Activities at home such as cooking and gardening, also may present eye injury risk. Use protective eyewear when participating in sports, using chemical cleaners or doing heavy yard work.
Do not look into a closed container of hot food (especially liquids) immediately after removal from a microwave oven as steam can burn the eyes.
Do not use eye medication prescribed for someone else.
Do not use another person's eye make-up and do not apply make-up in a moving vehicle.
When removing a cork from a bottle, wrap the cork in a towel and direct the bottle away from your face and away from others.
To minimize eyestrain associated with extensive computer monitor use: blink frequently; change your body, head and eye position often; place reference material as close to the screen as practical to reduce head and eye movements; and minimize glare and reflections from office lighting.
Be aware of cigarettes or cigars in your hand when around children.
Keep chemicals, spray cans, adhesives, scissors, knives, forks, keys, pens and pencils away from young children.
If you experience an eye injury, sudden pain, loss of sight, flashing lights, an increase in floaters or other changes in your vision, visit your eye care professional immediately.
Eye Disease Statistics
In America today:
80 million people have potentially blinding eye disorders.
14 million people have severe visual conditions not correctable by glasses.
14 million diabetics risk loss of sight.
12 million people have motor sensory diseases such as amblyopia and strabismus.
11 million people experience corneal disorders such as herpes and dry eye.
10 million people suffer visual loss caused by macular degeneration.
Age-related macular degeneration (AMD) is the chief cause of blindness among Americans over 50 - and South Florida has the largest concentration of AMD patients over the age of 65.
5.5 million people have cataracts that obstruct vision.
2.8 million people are colorblind.
2.3 million people endure visual losses from inflammatory diseases such as uveitis.
2 million people are visually impaired from glaucoma.
1 million people are legally blind.