This is a loss of eyesight that makes everyday tasks difficult.
A person with low vision finds it difficult or impossible to accomplish activities such as reading, watching television,
driving a car or recognizing faces.
When vision cannot be improved with regular eyeglasses, medicine or surgery, people with low vision need
rehabilitation to learn how to make the most of their remaining sight and keep their independence.
Vision Loss
Classification patterns of vision loss include:
| CLASSIFICATION | FEATURES |
|---|---|
| Central vision | This is the detailed vision we use when we look directly at something. Age-related Macular degeneration (AMD) affects central vision. Diabetic retinopathy can affect central or peripheral vision |
| Peripheral vision |
This is the less detailed vision we use to see everything around the edges. Glaucoma affects peripheral vision first. Strokes can affect one side of the peripheral vision |
| Contrast sensitivity |
This is the ability to distinguish between objects of similar tones like milk in a white cup or to distinguish facial features. All eye problems can decrease contrast sensitivity |
| Depth perception |
This is the ability to judge the position of objects. New vision loss in one eye can affect depth perception, such as the height of a step |
| Visual processing |
The lens in our eye focuses light rays onto our retina. The retina converts these light rays into signals that are sent through the optic nerve to our brain, where they are interpreted as the images we see. A problem with any of these processes affects our vision in various ways |
Causes of vision loss
- Congenital (e.g., prenatal or postnatal trauma, genetic or developmental abnormalities)
- Hereditary (e.g., retinitis pigmentosa or Stargardt’s macular degeneration)
- Acquired conditions (e.g., ocular infection or disease, trauma, age-related changes, or systemic disease)
Clinical features
- Loss of the ability to read standard-sized print
- Difficulty performing work-related tasks or leisure activities
- Inability to recognise faces or familiar people
Investigations
- History, visual Acuity
- Refraction
- Ocular motility
- Binocular Vision Assessment
- Visual Field Assessment
- Ocular Health Assessment: external examination, Slit lamp exam, tonometry, fundoscopy with dilated pupil
MANAGEMENT
- Low vision aids
- Mobility instruction and community based rehabilitation
- Co-management with optometrist, low vision worker, community rehabilitation worker
- Counselling services (psychiatric, psychological and social work)
- Occupational therapy