Myopic Macular Degeneration
Myopic macular degeneration can occur in people who are severely short-sighted due
to extreme elongation of the eyeball. The stretching of the retina can result in tears in
the macula and bleeding beneath the retina.
How the eye works
Light passes through the cornea at the front of your eye, and is focused by the lens
onto your retina. The retina is a delicate tissue that lines the inside of your eye. The
retina converts the light into electrical signals that travel along the optic nerve to your
brain. The brain interprets these signals to “see” the world around you.
Light from the object you are looking at directly is focused onto a tiny area of the
retina called the macula at the back of the eye. The macula is about 4mm across and
is responsible for detailed central vision and most colour vision. It provides the vision
you need to read, recognise faces, drive a car, see colours clearly, and any other
activity that requires detailed, fine vision. The rest of the retina gives you side vision
(peripheral vision).
What is myopia?
Myopia, often known as “being short-sighted”, causes vision to be blurry in the
distance but clearer when looking at things up close. It is a very common condition
of the eyes and, for most people, it can easily be dealt with using contact lenses or
glasses which will make vision clear and crisp.
Most people have myopia because their eyeball has grown too long or their cornea
(the clear window at the front of the eye) is more steeply curved than usual. These
differences cause a problem with the way the eye is able to focus light.
With myopia, the light coming into the eye from distant objects focuses in front of the
retina which makes vision blurry. Moving closer to an object changes the focusing of
the light and the object is then in focus on the retina and therefore looks clear.
To correct for this blurring, optometrists can measure focusing power and prescribe
corrective glasses or contact lenses. The strength of the lens required to correct sight
back to a normal level is measured in dioptres (D).
