Exercise and eye disease
In detail
detail. word document
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Exercise helps prevent many eye conditions, and the Royal College
of Ophthalmologists supports Government recommendations that we
take at least 30 minutes exercise a day to protect our sight. Those
of us with very sedentary jobs probably need more still, and generally
90 minutes a day is advisable. Children need at least 2 hours a
day.
Any exercise will help, such as walking, swimming, cycling, gardening,
housework, & washing up.
Overall lack of exercise probably causes about a quarter of heart
and brain disease as we get older, and so exercise is likely to
be very helpful for our sight.
Exercise helps prevent diabetes, diabetic retinopathy, macular
degeneration, helps glaucoma patients, and will help prevent other
conditions such as blocked retinal arteries and veins and cataracts.
Below are some examples as to how exercise will help prevent eye
disease. |
Diabetic Retinopathy |
In this condition the retina, the film at the back of the eye,
becomes damaged by the high sugar levels. The retina starts to
leak fluid, and also extra-weak blood vessels grow. Together these
damage the retina and sight is reduced.
In diabetes we do not have enough insulin. When we are short of
insulin we develop high blood-sugar levels, and the high sugar
levels then damage all parts of the body, especially our eyes.
Often a diet or drugs are sufficient to make the most of the body's
remaining insulin. However, many people with diabetes need extra
insulin which they have to inject.
Exercise helps by making insulin last longer. If the diabetes
is diet or tablet controlled, exercise will make the most of the
remaining insulin. If insulin is injected, it will therefore last
longer and so lower doses will be needed. In this way the diabetes
will be easier to control and the eye will not be damaged as much.
We now know exercise can prevent type 2 diabetes in the first
place as it helps to reduce the insulin the body needs. Some people
who develop diabetes could not have done anything to avoid it,
but regular exercise has been show to make type 2 diabetes much
less likely. |
Macular degeneration |
The macula is the centre of the retina..it is very important for
seeing faces, television, driving, and reading. As we get older
it can become damaged, and we lose our central vision. Side vision
stays normal, but without our central vision life can be a struggle.
Macular degeneration (ARMD) is
common as we get older, but we now know how to prevent some of
the damage.
Macular degeneration is worse in patients with high blood pressure
and high fat levels in blood. As exercise lowers blood pressure
and fat levels it is likely to prevent many cases of macular degeneration. |
Retinal artery and vein blockages |
The tiny blood vessels in the retina bring the nutrients into
the eye, and take the waste products out. These blood vessels are
part of the 'cardiovascular' system, and will be damaged in a similar
way to arteries in our heart and brain. In the eye this may result
in blockages of the retina or optic nerve veins or arteries.
Thus high blood pressure, high cholesterol, and high sugar levels,
and a diet without many vegetables and fruit, will be harmful.
Exercise is know to be very important in keeping the heart blood
vessels healthy, and is very likely to help the retinal and optic
nerve blood vessels. The likely result is fewer people with both
retinal vein occlusions and retinal arteriole occlusions, both
of which can cause severe loss of sight. |
Glaucoma |
Glaucoma is a condition in which the optic nerve becomes damaged
by pressure inside the eye (animation).
The optic nerve is the 'electric wire' which takes the messages
about what we see back to the brain, so if it is damaged our sight
is reduced.
The very tiny blood vessels in the optic nerve are very sensitive
to pressure in the eye.
Exercise lowers the pressure a little in the eye, and this will
improve blood flow to the optic
nerve . Exercise is therefore likely to reduce sight loss from
glaucoma. Although the effect is not great, it may add about 10%
to the effect of eye drops. |
Cataracts |
Cataracts are also more common in people with high blood pressure
and diabetes, so exercise would be expected to help prevent cataracts.
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