A healthy diet has a role to play in maintaining good eyesight, with
vitamin A holding the key to many eye disorders. Beta carotene, which
the body converts to vitamin A, is found in yellow and orange-colored
fruit and vegetables (apricots, mangoes, carrots, sweet potatoes and
squashes) and in dark green, leafy vegetables such as spinach and kale.
In the developing world, vitamin A deficiency is the most common cause
of blindness in people under the age of 21. The first sign of this
deficiency is usually night blindness - an inability to adapt to low
light intensity.
Macular Degeneration
Caused by the deterioration of part of the retina, macular degeneration
is a major cause of blindness in the elderly. One of the major risk
factors is prolonged exposure to bright light, and this has led to the
view that damage to the retina is caused by Free Radicals,
As vitamin E and beta carotene are believed to protect against free
radical damage, research has focused on diet and foods rich in these
two nutrients. A study at Harvard Medical School found that the degree
of degeneration was correspondingly less in those who had a higher
consumption of dark green vegetables which contain beta carotene.
Scientists speculate that lutein and zeaxanthin, two 'relatives' of
beta carotene, build up in the retina. There, they filter out the rays
at either end of the light spectrum that cause damage over many years,
thereby making the eye less vulnerable.
Certain vitamins and minerals have been claimed to help to retard
macular degeneration: eat plenty of fresh fruit and vegetables for
vitamin C; wheatgerm, seafood and pulses for zinc; lean meat, poultry,
fish, nuts, whole grains and green vegetables for B vitamins; and
include cold-pressed seed oils and avocados for vitamin E.
Bioflavonoids, which are found in citrus fruits and bilberries, may
also help.
Conjunctivitis
The delicate membrane covering the front of the eye can become inflamed
as the result of an infection or an allergy, producing the condition
known as conjunctivitis or 'pink eye'. If the redness forms a ring
around the front of the eye, it may be due to a deficiency of
riboflavin. Soreness and a reddening and cracking at the outer corners
of the eyes may also signal a lack of this B vitamin, which is found in
milk, whole grains and offal.
Glaucoma
A build-up of fluid pressure in the eye is known as glaucoma. It is
most common among people aged 40 or over and tends to run in families.
Symptoms include blurred vision, a halo effect around lights and
difficulty seeing in the dark. Glaucoma has been linked with a
deficiency of thiamin, found in meat, fish, poultry, whole grains,
pulses and nuts, and of vitamin A, abundant in liver and eggs, and also
derived from orange-colored plant foods that contain beta carotene.
Seek medical attention immediately if any of the above symptoms appear.
Cataracts
This painless clouding of the lens of the eye is most common among the
elderly, but can occur in younger people because of a rare metabolic
defect. It is believed that cataracts are the result of oxidation
occurring in the lens of the eye, and vitamin C helps to protect
against this type of damage. Riboflavin, found in milk, wholegrain
cereals and yeast extract, may also offer some protection, as may
increased intakes of vitamin E and selenium. The ability of the eye to
metabolise a sugar called galactose appears to decrease as we grow
older. This, combined with a high level of galactose in the blood,
which occurs in the inherited condition known as galactosaemia, may
also trigger the formation of cataracts.
Other Eye Problems
Diabetics are prone to a condition in which the capillaries in the
retina leak fluid or break. This is a major cause of blindness.
Supplements of vitamin C have been found to have some protective effect
upon the blood vessels of diabetics, so it is possible that a high
intake of vitamin C, from fresh fruit and vegetables, may be helpful.
Good overall control of diabetes appears to result in fewer eye
complications.
Styes - small red boils on the glands that lubricate the eyelashes -
are caused by bacteria and usually come to ahead and heal in a few
days. Recurring styes may be a sign of poor nutrition, stress or of
being run-down.
