Search by name
logo

Vision Impairment

Vision impairment is when a person’s vision does not work as well as it should. The most common reason for this worldwide is when people need corrective lenses (glasses or contact lenses) but do not have access to them.

Symptoms

People with vision impairment can be classified as either near-sighted or far-sighted. Near-sighted people can see close objects clearly but have difficulty seeing objects farther away. Far-sighted people can see far away objects clearly but have difficulty with closer objects.

People with vision impairment can also lose all or part of their visual field. The visual field is everything a person can see, including in their peripheral vision. A loss in part of the visual field means a person must turn their head to be able to see objects clearly.

Causes

Some common causes of visual impairment include:

  • Uncorrected refractive error – when the eye is not able to bring objects into focus. This is very common worldwide. Refractive errors happen when a person’s eyeball is not the correct shape. for optimal focus. Glasses or contact lenses correct this.
  • Cataracts – when the lens of the eye becomes cloudy.
  • Diabetic retinopathy – when high blood sugar from diabetes damages the blood vessels in the back of the eye. Untreated, it can cause blindness.
  • Glaucoma – an eye condition where the pressure inside the eyeball is too high and eventually causes damage to the optic nerve. Left untreated, it can cause blindness.
  • Macular degeneration – an eye disease where a problem at the back of the eye can cause the middle part of a person’s vision to become blurry or to look like a black spot.
  • Congenital disorders.

Risk Factors

Some risk factors for vision impairment include:

  • Aging
  • Uncontrolled diabetes
  • Uncontrolled high blood pressure
  • Genetics
  • Living in an area without easy access to an optician or glasses

Diagnosis

An optician or ophthalmologist performs an eye examination which usually includes:

  • Snellen test – where a person is asked to stand a certain distance from an eye chart which has increasingly smaller letters and numbers.
  • Visual fields test – a test to make sure a person’s peripheral vision is correct.
  • Dilation of the pupil (black spot in the centre of the coloured part of the eye) – the doctor places a special eyedrop into the person’s eye to artificially enlarge the pupil. This allows the doctor to better examine the back of the eye. The pupil goes back to normal within 24 hours.
  • Shining a bright light into the eye to see whether the pupil reacts properly.
  • Non-contact tonometry – commonly called the “puff of air” test, a light puff of air is blown into the eye to test the eye pressure.

An eye exam may also include use of a slit lamp, a special instrument that allows the provider to see to the back of the eye. This is most effective with dilated pupils.

Treatment

Treatment depends on the cause of visual impairment. For refractive errors, a prescription for glasses or contact lenses is often sufficient. A person may otherwise be given eye drops or other types of medications. Some types of visual impairment are permanent.

Complications

Visual impairment has several potential complications, including:

  • Falls which can lead to broken bones
  • Less quality of life
  • Having a hard time going to school
  • Difficulty finding and keeping a job
  • Needing others’ help with daily activities and self-care
  • Feeling depressed or anxious
  • Less able to care for other medical conditions
  • Difficulty with transportation

In children with visual impairment, potential complications include:

  • Not reaching their full potential at school
  • Being bullied or abused while in school
  • The affect of other conditions leading to disability

Prevention

The best way to maintain eye health is to get regular eye exams, wear corrective lenses if needed and maintain good eating habits.

 
 
 

The content appearing on this site is not intended to treat, diagnose, or provide health care advice. The articles you read here are meant for informational purposes only. Please review additional information to learn more.