Terminology
These are the different terms used for stages of visual impairment.
- Severely Sight Impaired (SSI) previously Blind
- Sight Impaired (SI) previously Partially Sighted
- Registered Severely Sight Impaired or Sight Impaired
- Low Vision
The following information is intended to give:
- Provide a general understanding of visual impairment and eye conditions.
- Awareness of the impact of visual loss on daily life.
- Understanding the practical solutions to some of the issues that come with a visual impairment.
- Promote best practice in interacting with someone with visual impairment.
Vision and Age
- As we get older our sight deteriorates in one way or another.
- Many of us will require a reading prescription when we reach our 40’s.
- Many eye diseases are a result of ageing, and in particular macular degeneration is directly linked to age.
- Other conditions that can appear in later life are Glaucoma, Cataract and Diabetic Retinopathy.
Eye Conditions
- Macular degeneration
- Glaucoma
- Diabetic retinopathy
- Nystagmus
- Retinitis Pigmentosa
- Cataracts
- Neurological Vision Loss


Macular Degeneration
- Macular degeneration is one of the leading causes of sight loss in our ageing population.
- Your Macula is responsible for your central vision and fine detail.
- This is an example of central field loss, causing problems with face recognition and reading among other symptoms.


Glaucoma
- Glaucoma is a condition which affects the optic nerve.
- Most common form is Primary Open Angle Glaucoma (POAG).
- Damage to the optic nerve results in field loss and early stage field loss is pictured here.
- Early diagnosis and careful monitoring can help prevent further deterioration.
- Condition is lifelong and irreversible, but treatment is very effective.


Diabetic Retinopathy
- Complication of diabetes
- High blood sugar levels can damage the blood vessels in the retina
- Can be treated with laser, which may damage your vision.


Retinitis Pigmentosa
- Hereditary eye disease affecting the retina
- Very restricted field of vision
- Night blindness
- Can lead to total Blindness


Cataract
- Ageing of the lens in the eye resulting in cloudiness.
- Can be age-related, congenital or as a result of trauma.
- Affects visual acuity, like looking through a net curtain.
- Usually treated successfully with surgery, by replacing the lens.


Reduced Visual Acuity
- Here is an everyday object seen from different perspectives with different degrees of visual acuity.
- Notice how colour and contrast is important in deciphering the nature of the object.

Neurological Vision Loss
- Umbrella term for numerous eye conditions.
- These conditions often go unnoticed.
- Most common is Homonymous Hemianopia, as a result of a stroke.
- Neurological visual impairments often involve the loss of central vision, one side of the visual field, or a loss of the entire visual field.
Homonymous Hemianopia

Visual Strategies
- Bigger: Magnify or move closer.
- Bolder: Increase font size, use contrast.
- Brighter: Make it brighter, use colour.
- Maximising existing vision by using scanning techniques if you have a field loss.
- Putting strategies in place for reading e.g. eccentric viewing and magnifiers/aids.
Use of Contrast
This is an example of good contrast, allowing the cup to stand out on the black background.