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

  1. Macular degeneration
  2. Glaucoma
  3. Diabetic retinopathy
  4. Nystagmus
  5. Retinitis Pigmentosa
  6. Cataracts
  7. Neurological Vision Loss
Macular Degeneration ImageMacular Degeneration

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.
GlaucomaGlaucoma

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.
Macular Degeneration Image

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 1

Retinitis Pigmentosa

  • Hereditary eye disease affecting the retina
  • Very restricted field of vision
  • Night blindness
  • Can lead to total Blindness
Retinitis Pigmentosa 1Cataract

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.
Seescape Logo

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

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.