Visual Impairments:

Definition

Visual impairments include people who have never had any visual function, those who had normal vision for a time before becoming gradually / suddenly partially or totally blind, those with disabilities in addition to the visual loss, those with impairments of parts of the visual field, and those with a general degradation of acuity across the visual field. Persons who have visual impairments have a best corrected visual acuity of 20/70 or less in their better eye, or may experience difficulty with optic muscle control.

• Characteristics of Low Vision:
  
  Limited ability to visually absorb their "out of arm's reach" environment
  Field of vision or muscles may be affected
  Possible color blindness
  Migraines headaches and/or debilitating fatigue after long periods of reading
  
  
• Legally Blind - A person who has visual acuity of 20/200 or less in the better eye even with correction (e.g., eyeglasses) or has a field of vision so narrow that its widest diameter subtends an angular distance no greater than 20 degrees. May not "appear" to have a visual disability, but will need accommodations in order to read printed materials and/or function within an unfamiliar environment.

• Blindness - Persons who are blind experience a complete lack of vision, though they may have some perception of light and colors. They often depend on other senses, such as hearing and touch, to gather information. Individuals who are blind do not always have the experience of sight from their past to assist in the recollection of data, so it is not appropriate to assume that someone who is blind is familiar with objects in the class room or a new environment. They may use canes and/or seeing-eye dogs in order to navigate their environment.