Two women are standing in front of a counter with a potato, cutting board and two bowls. The woman on the left in pink is peeling the potato, while the woman on the right, wearing green, if overseeing.

What is blindness?

Main Content

Many people imagine blindness as complete darkness. But that’s not entirely true.

The term “blindness” covers a broad spectrum of visual disability, from when your sight is impaired enough to interfere with daily activities like reading, cooking or driving, up to total blindness.

Each person’s experience of blindness is unique. Blindness has many causes, and each affects eyesight differently:

  • retinal diseases like age-related macular degeneration create distortion or blind spots in the central vision.
  • diseases like glaucoma and retinitis pigmentosa impact peripheral sight, creating “tunnel vision.”
  • genetic conditions like albinism cause low vision and make people highly sensitive to light.
  • eye conditions like nystagmus affect how the eyes move and coordinate, reducing vision and depth perception.
  • some congenital conditions may impair sight, leaving someone with only light perception.
  • damage to the optic nerve, which sends signals from the eye to the brain, or an injury to the part of the brain that processes information from our eyes can affect the ability to perceive or recognize objects or visual information.

Legal blindness

Legal blindness is a level of blindness that has been defined by law to limit some activities for safety reason, such as driving, or to determine eligibility for disability-related government programs and benefits.

Someone is considered to be legally blind when:

  • visual acuity is 20/200 (or 6/60) or less in both eyes after correction, and/or
  • a visual field of 20 degrees or narrower.

You do not need to be legally blind to access services from the CNIB Foundation, Vision Loss Rehabilitation Canada or other CNIB organizations. As soon as your eyesight begins to affect your daily life, you’re eligible.

Deafblindness

Deafblindness is a combined loss of hearing and vision that results in significant challenges accessing information. Some people are born with Deafblindness, while others acquire it later in life.