Definitions                                                                                               

 

 

Blindness

Sometimes referred to as “total blindness,” this term describes a person’s inability to see anything at all1, although some individuals who are blind may perceive shadows.

 

 

Legally Blind2

A person who is legally blind many times has some level of useable sight.  In fact, nearly 90% of legally blind persons have some remaining vision.  This term is often used to determine eligibility for benefits. 

 

A person is considered legally blind if their central vision is equal or worse than 20/200 in their better eye, and/or if their field peripheral vision is limited to a diameter of 20 degrees or less.  Generally, those that are legally blind cannot read the biggest letter on an eye chart, even with glasses or contact lenses, and/or have very limited peripheral (side) vision.

 

 

Visually Impaired or Vision Impaired

A person is considered visually impaired if their vision is 20/70 or worse in the better eye even with glasses.  Contrast, lighting, glare, and other factors can also affect the level of visual impairment1.

 

This term can be all encompassing to refer to those who have trouble seeing even when wearing glasses or contact lenses, as well as those who are completely blind.  Sometimes the term “low vision” is also used, although this does not refer to those who are completely blind.

 

Colorblindness

Colorblindness does not mean a person cannot see any color, but it does mean that the person has trouble deciphering between certain colors.  Most commonly, those that are colorblind cannot tell the difference between red and green, as well as similar shades of color such as dark brown and hunter green.  Colorblindness is nearly always caused by heredity.  It is extremely unlikely for females to be colorblind.

 

 

 

White Cane

The White Cane is a symbol of the blind community and is used by many blind and visually impaired people as a mobility tool.  There are different types of White Canes, including the traditional Long Cane used to detect objects in a person’s path as well as a change in terrain, and the Support Cane, which also helps with stability.  White Canes are also used as a courtesy.  The symbolic Canes notify others of a person’s visual impairment so that they may kindly give the right of way when walking.

 

35% of legally blind persons use a White Cane2, and in most states drivers must stop at any crosswalk if a pedestrian with a White Cane is crossing.

 

Guide Dog

Formerly referred to as “seeing eye dogs,” guide dogs are specially trained to lead their blind and visually impaired owners while walking.  Owners receive special mobility training to learn how to appropriately direct the guide dog.  Working as a team, a guide dog and its owner safely navigate. 

 

Golden Retrievers, Labradors, and German Shepherds tend to be more appropriate for this type of training.  About 2% of legally blind persons use guide dogs2.

 

Braille

Braille is a code using a series of bumps or raised dots that allows/assists the blind and visually impaired to read using their fingertips.  Grade 1 Braille uses Braille cells (the raised dots) to represent each letter individually, while Grade 2 Braille is a system that uses combinations or contractions to minimize the number of Braille cells needed.  Braille is commonly written using a braillewriter – a typewriter that punches Braille into paper.

 

 

 

 

 

Definitions referenced from the 1American Foundation for the Blind and 2Braille Institute.