Blind / Visual Impairment Basics

Understanding Terms

Visual impairment is a general term used for vision loss that glasses or contacts cannot fully correct. It includes low vision, where a person still has some sight but has trouble with daily tasks like reading or moving around familiar and unfamiliar spaces, and blindness, which is having little or no usable vision. People use many different terms to describe vision problems because there are many causes and different symptoms. To understand this better, we will look at some of the most common words used to talk about vision loss.

Visual impairment, including blindness, means an impairment in vision that, even with correction, adversely affects a child’s educational performance.  

Legal Blindness is defined by having a visual acuity of 20/200 or worse in the better eye with the best possible correction or having a visual field of 20 degrees or less in the better eye.  

Light perception describes the ability to perceive the difference between light and dark, or daylight and nighttime.

Total blindness is a condition in which a person has no usable vision in either eye. This means they cannot perceive any light or distinguish between darkness and light.  

Cortical or cerebral visual impairment (CVI) happens when parts of the brain that help us see are damaged. In CVI, the eyes might appear to work normally when tested, but the brain has trouble making sense of what the eyes send it. This problem makes seeing and understanding things hard. CVI is the main cause of blindness and low vision in children.

Deafblindness means concomitant hearing and visual impairments, the combination of which causes such severe communication and other developmental and educational needs that they cannot be accommodated in special education programs solely for children with deafness or children with blindness. 

Low vision is often explained by having a moderate or severe visual impairment that impacts everyday activities and cannot be corrected with glasses, contacts, or surgery. 

To learn more about visual impairment and blindness

Introductory Series on Deafness and Blindness: Assessments

Learn more about the specialized assessments for learners who are deaf, hard of hearing or blind, visually impaired

Supporting Learners Series: Students Who Are Blind or Visually Impaired

When learners are healthy, safe, engaged, challenged, and supported, they are more likely to enjoy learning, develop positive social skills, and achieve greater success. Find out how teachers of the visually impaired are working with teams to address the whole child in this online module series.

Promoting Access for People Who are Deaf, Hard of Hearing, Blind, or Visually Impaired

This online training will get you started with tools and strategies, and empower you in strengthening your connections at home, at school, and in the community.

Ohio Guidelines for Working with Students who are Blind or Visually Impaired

Explore the tool developed to provide families, staff, and administrators with a set of guidelines and information regarding services needed to support the implementation of educational goals for students.