Low Vision
Most people with vision loss are not completely blind but have what is referred to as “low vision”.
This is where one is partially sighted and it can vary in severity to just about being able to perceive light to being able to make out objects and shapes.
Only 15% of people with vision loss are totally blind the other 85% have some level of vision however small.
The definition of low vision is a visual acuity of 20/70 or poorer in the eye with best vision that cannot be improved with either surgical or corrective lens intervention.
Being legally blind on the other hand means that a person has a visual acuity of 20/200 or less in the best seeing eye.
What do these visual acuities mean?
A visual acuity of 20/70 means that a person with this visual acuity can see an object 20 feet away that a person with perfect 20/20 vision can see 70 feet away.
To carry that onto the legally blind definition, this person can see an object 20 feet away that a visually unimpaired person can see 200 feet away.
Low vision can also relate to a loss of the peripheral visual field rather than just the central vision. This is often experienced as blind spots in the visual field or tunnel vision.
Causes of low vision
The following conditions can cause low vision and in some cases vision loss
Cataracts
Retinitis pigmentosa
Glaucoma
Diabetic retinopathy
Macular degeneration
Hereditary eye conditions
Low vision Effects
Low vision can have both practical and emotional effects.
There is a need for to assess the physical needs of the individual to see if they need a cane, a magnifying glass, aids around the house etc.
The emotional wellbeing is also very important. The individual should be given details of the appropriate psychological supports and details of how to deal with having low vision whilst living life to the full.
Children with low vision may need assistance and support with learning and social skills which should be dealt with at an early age.
Treatment of Low Vision
The first thing to do when assessing a person with low vision is to pin point the cause.
If a specific ocular condition is causing it must be treated if possible.
Many of these eye condition cannot be cured but the progression of the disease can be slowed down through surgical intervention or medication.
Low Vision Products
There are many low vision products to make life easier to those with visual impairment
These include
- Telescopic glasses
- Reading prisms
- Magnifying glasses
- Handheld and freestanding magnifiers
- Lenses that filter blue light
- Closed-circuit television
Some non-optical aids include
- Text-reading software
- High-contrast clocks and watches
- Large-print publications
- Clocks, phones, and watches with large numbers
- Audio DVD
Prevention
The best way to prevent low vision or vision loss is to eat a healthy diet rich in luteins and zeaxanthins which helps slow down or prevent macular degeneration.
Protecting the eyes from UV exposure help prevents cataracts and getting regular eye exams means that certain eye conditions like glaucoma can be treated early and prevented with speedy treatment.