Module 3: Vision
Qualification Criteria for Visual Impairment in K–12
A student's functioning may be described by one of the following:
- A visual acuity of 6/21 (20/70) or less in the better eye after correction
- A visual field of 20 degrees or less
- Any progressive eye disease with a prognosis of becoming one of the above in the next few years
- A visual problem or related visual stamina that is not correctable, and that results in the student functioning as if his or her visual acuity is limited to 6/21 (20/70) or less
The B.C. Ministry of Education defines visual impairment as a visual acuity estimate of 20/70 or less in the better eye with correction and a visual field limited to 20 degrees or less. A student may also qualify as visually impaired if their functional vision will meet these criteria within the next two years, or if their visual condition results in clinically significant visual fatigue that negatively impacts the student’s ability to engage their vision for learning.
A visual acuity estimate of 20/70 indicates that a student would need to come to within 20 feet of a visual target to see it with the same clarity as a student with typical 20/20 vision would see from 70 feet. Mathematically speaking, this represents a 3.5 times difference (or greater) from unimpaired visual acuity.
A visual field estimate of 20 degrees or less indicates that without moving their head or eyes, a student can gather visual information around 10 degrees or less from each side of midline (a central fixation point). By comparison, an unimpaired visual field allows the student to gather visual information in a 180-degree arc from temple to temple.