A person with sight loss may be registered as sight impaired or severely sight impaired. If a person is registered as severely sight impaired, it doesn’t necessarily mean that they have no sight at all. Quite often, a condition can leave an individual with limited vision and be registered sight impaired due to the level of useful vision left. Shadow vision, light and dark perception, peripheral and tunnel vision are caused through certain sight conditions. For example:
A cataract is a clouding of the lens within the eye. The cataract is like frosted glass causing blurred or misty vision. You may be dazzled by bright sunlight and colour vision may become washed out or faded.
Glaucoma is an eye condition where the optic nerve, which connects your eye to your brain, becomes damaged. It can lead to loss of vision if not detected and treated early on. It usually occurs when the fluid in the eye cannot drain properly, which increases the pressure inside the eye and puts pressure on the optic nerve.
Age-related macular degeneration (AMD) is a degenerative condition that affects your central vision leaving you with peripheral vision only and can lead to shadow vision. Detailed tasks such as reading, writing and looking at photographs are affected by this condition. This is the leading cause of sight impairment in those over the age of 50.
Retinitis pigmentosa (RP) is the name given to a group of inherited eye conditions that affect the retina at the back of your eye causing permanent changes to your vision, but how much and how quickly can really vary from person to person. This affects your side vision leaving you with tunnel vision making it harder to see in dim light or the dark.