||The retina is like a thin
membrane that covers the back two thirds of the inside of the eye.
Like the film in a camera, it receives light and transmits signals through
the optic nerve to the brain, allowing us to see. Diabetes may cause
blood vessels nourishing the retina to leak fluid or blood that can scar
the retina causing blurred vision and eventual blindness. This
condition is called Diabetic Retinopathy.
||A group of diseases
characterised by increased pressure inside the eye. If left
untreated, causes blindness through permanent damage to the optic
nerve. Sometimes called "thief in the night" because there
are often no symptoms until damage has been done.
||A degeneration of the central
portion of the retina (macula) which is responsible for straight-on vision
used in driving, reading, perceiving colours, and recognising faces.
The most common cause of blindness in people over 50 years of age.
||A vision problem caused by an
irregularly shaped cornea. Light rays enter the eye through a smooth
cornea (equally curved in all directions) and focus at a single point on
the retina producing clear vision. With astigmatism, light rays
enter the eye through an irregularly shaped cornea and do not focus at a
single point. This produces a blurred or distorted image on
||A condition in which the
visual images come to a focus in front of the retina of the eye, resulting
in defective vision of distant objects. Myopia is commonly known as
||A clouding of the lens of the
eye. Usually occurs over a period of years and is caused by a
chemical change in the protein which makes up the lens. Most people
over the age of 70 have cataracts.
||A condition in which visual
images come to a focus behind the retina of the eye and vision is better
for distant than for near objects. Hyperopia is commonly known as
||A condition in which the eye
is unable to focus on close objects due to a loss of elasticity in the
lens. Usually occurs after the age of 45.