Cause of Blindness

What is Blindness & what is the cause of blindness?



Blindness is a very disabling eye health condition. It is defined by the loss of normal or correctable vision. Partial blindness is the loss of only part of the vision. Complete blindness is when there is no perception of light. People with a vision worse than 20/200 are considered legally blind. Blindness occurs most often with advancing age and will be notable as the population ages. Vision need not be lost needlessly as many causes of blindness can be prevented.

Accidents / accidental trauma to the eyes (such as racket ball, fireworks, chemical burns, or injuries from bungie cords, fishing hooks, and similar objects), accidents at the workplace and the home can be prevented with good eye protection and safety practices.

The following cause of blindness are non-accidental:

  • Diabetic retinopathy is one of the complications associated with diabetes. Early treatment often improves the potential for saving sight. Every diabetic should receive regular care from a doctor and be screened for retinopathy even before any visual symptoms appear.
  • Age-related Macular degeneration (AMD) is a degenerative disorder affecting the macula. It tends to occur in those aged 65 and older. The person may notice straight lines appearing wavy, letters in newspapers, books and magazine appearing blurry or dark, empty spaces block the centre of vision. The best defence against AMD is early diagnosis by an eye specialist.
  • Glaucoma is due to a build-up of pressure within the eye. This pressure can cause damage to the cells that form the optic nerve, the structure responsible for transmitting visual information from eye to the brain. The damage is progressive with loss of peripheral vision first, followed by reductions in central vision and, potentially, blindness. At least half of those who have glaucoma are unaware of it. Those who have a family history of glaucoma, are diabetic or very near-sighted are more likely to develop glaucoma.
  • Unfortunately, there is no simple test to screen glaucoma. A complete eye examination through dilated pupils together with other specialised test by an eye specialist is needed.

    In the early stages of glaucoma, there are few signs and symptoms. Later, the person may notice loss of side vision, inability to adjust the eye to darkened room, difficulty focusing on close work or rainbow coloured rings or halos around lights.

    The cause of blindness can be detected early and treated appropriately. Any sight that is destroyed cannot be restored, but medical and surgical treatment can help the disease from progressing.

  • Retinal detachment is another cause of blindness. It tends to occur with ageing. The vitreous fluid (the gel-like material that fills the eyeball) shrinks as we age. This is a normal process that usually does not cause retinal damage. However, inflammation or myopia (nearsightedness) may cause the retina to be pulled and can lead to its detachment. Others at risk includes those who have had previous eye surgery, suffered an eye injury, a family history of retinal problems and/ or diabetes.

    Symptoms of a possible retinal detachment include a blind spot, blurred vision, shadowy lines, flashes of light and/or floaters (spots). Floaters are a normal part of the eye's ageing process and do not necessarily signal a retinal detachment. However, a sudden onset of floaters appearing in large numbers indicate a need to check for retinal detachment.

If you suspect there is a eye health problem, see an eye specialist immediately. The doctor needs to act quickly to detect any potential cause of blindness, repair and prevent permanent vision loss.