The outer portion of the eye is the cornea, allowing light spherical bulge can enter the eye. The light then passes through the pupil, transparent space located in the middle of the iris. Behind the pupil, there is a lens that is connected to the zonules. Zonules are fibers that serve muscles tighten and relax the focus.
Light entering through the lens and the retina, the tissue at the back of the eye. Retina then sends the signal through the optic nerve to the brain to translate what is seen by the eye.
Ages 0 - to 30-yearAt birth, the lens inside the eye, usually colored clear and flexible. Zonules that connected to the eyepiece is still strong.
As you age, the lens becomes less flexible, and zonules are not effective, thus requiring corrective lenses. If the eyeball is too long, It will be nearsighted.
If the eyeball is rather short, then there was farsighted. Each time feeling the change vision, you should immediately come and meet to eye doctor (oculist).
To avoid damage your vision, do eye exercises as directed by oculist. Reading and watching must be in healthy.
In 40 year Olds"This age is, when people begin to lose the ability to focus vision at close range. Condition is called presbyopia," said Dr. Andrew Iwach, spokesperson for the American Academy of Ophthalmology and executive director of the Glaucoma Center of San Francisco as reported by FoxNews on Tuesday (20/3/2012).
The cause is a lens that retracts, harder and zonules are weakened. For correcting vision, use reading glasses. How fast is the occurrence of presbyopia is different for each person.
"If you always have perfect vision, reading glasses may be used only at the early age of 40 years. People who have nearsightedness is more resistant to this disorder and often do not see any change in vision due to age presbiopi reached the end of 40 years," said Jill Koury, assistant professor of ophthalmology at the University DukeEye Center, in Durham, North Carolina.
50 Year old and moreat this age, lens more hard, and may be needs to use strong corrective lens. This age also have risk for get eye disease as below:
Occurs when the eye's lens becomes cloudy. More than 20 million Americans have cataract. The main cause of this disease is aging. Smoking and sun exposure also trigger cataracts. If not treated, can lead to blindness.
The disease is associated with a form of pressure inside the eye which causes damage to the optic nerve. Glaucoma causes loss of vision slowly and eventually lead to blindness. This disease is one of the most common reasons leading cause of blindness worldwide.
3. Damage to the macula.
The macula is a part of the retina. The macula may be damaged due to heredity or environmental factors that lead to impaired vision.
The study found that a combination of vitamin C, beta carotene (vitamin A-forming), vitamin E and zinc can reduce the risk of macular degeneration.