Your eyes are essentially an amazing sort of camera. They
take pictures of the world around you and send the pictures to your brain, so
that your brain can work out what your eyes are seeing. This happens from the
moment that you open your eyes in the morning to when you close your eyes at
night.
When you look at an object, the light from it enters your
eye through the pupil. The iris changes the size of the pupil, depending on how
bright the light is. The lens focuses the light onto the back of the eye: the
retina. The retina is a mass of light-sensitive neurons, called photoreceptors,
which change light signals into electrical ones.
Photoreceptors contain chemicals that change when they are
hit by light. This causes an electrical signal, which is then sent to the brain
along the optic nerve. Different types of photoreceptor allow us to see an
enormous range of light, and all of the colours of the rainbow. And all of this
is happening right now as you read this!
Sight is an amazing gift, and unfortunately not one everyone
is born with. Blindness and sight loss affects almost two million people in the
UK. The most common causes of blindness and sight loss are:
Age-related macular degeneration (AMD) - an eye condition resulting in the loss of central vision.
Diabetic retinopathy - a common complication with eye sight
which is due to the condition diabetes.
Cataracts - An eye condition where the lens part of the eye
becomes clouded.
Glaucoma - an eye condition where the optic nerve is damaged
leading to sight loss. In the UK, glaucoma affects two in 100 people over the
age of 40.
Retinitis pigmentosa - a group of hereditary eye disorders
which affect the retina.
If you suffer from sight lose or are blind and need help and
support, please contact us.
We provide opportunity, support, friendship and
services to blind and partially sighted people in Sheffield, helping them to
achieve whatever they wish to do and whatever they aspire to be.
