Vision is an essential aspect of development and learning. For many children, the learning process is heavily supported by the visual sense with information acquired from initial input through their eyes. It is commonly accepted that up to 80 percent of learning is through vision with input and coordination with other senses.
Visual impairment is an umbrella term that encompasses a wide spectrum of visual functions ranging from moderate vision loss to blindness. Visual impairment is a collective term that includes individuals who are blind, have low vision, or have neurological visual impairments such as cortical/cerebral visual impairment or other trauma to the brain’s visual components. It is most often caused by a disease, disorder, syndrome, or brain injury. A visual impairment may progressively worsen, stabilize, or improve depending on the diagnosis. It most frequently impacts a student’s ability to see visual detail at a distance or near (visual acuity). It also includes non-seeing or distorted areas within a student’s visual area (visual field) that may result in significant visual instability during visual activities such as reading. It may also interfere with daily activities and safe mobility. Additional visual skills and factors affected by visual impairment may include the ability to:
- see low contrast visual detail;
- tolerate bright light and glare;
- adapt to changes in environmental illumination,
- maneuver safely due to difficulties with stereovision, or depth perception; and,
- discern complex visual information.
Visual deficits in these areas adversely impact a student’s ability to learn and perform daily activities, as well as affect the student’s orientation and mobility.
Educational Visual Impairment
The educational definition of visual impairment, as outlined by IDEA, determines eligibility for special education services and the need for specially designed instruction to access the educational curriculum across multiple settings. Unlike medical definitions of visual impairment, the educational definition does not stipulate any diagnostic criteria measurements (e.g., visual acuity such as 20/70, a visual field such as less than 20%) nor diagnosed eye condition. While it is best practice to ask for an eye report during the assessment for eligibility and reevaluation process, one cannot be required, nor can a visual acuity and/or visual field range be stipulated.
Different Definitions of Visual Impairment
The IDEA definition of visual impairment is broad in scope. This is to ensure that a student’s functional vision is not negatively impacting their ability to access their educational program. These services are designed to provide necessary supports and services to meet the unique needs of each learner. However, students who qualify for educational vision impairment services may be excluded from additional services outside of the educational environment. This is due to the more limited definition of visual impairment that organizations and community services providers may have. The simple fact is that there is not one set definition accepted by the education community, the medical community, and the government. Therefore, a student and their family must understand that while in school the student may be recognized as having a visual impairment but may not be recognized as such by organizations such as the Office of Vocational Services’ Bureau of Blindness and Visual Services, University Disability Services, or Social Security. To see a sample of different visual impairment definitions refer to the table “Examples of Visual Impairment Definitions.”
Examples of Visual Impairments
| Individual with Disabilities Education Act (IDEA) |
World Health Organizaion (WHO) |
National Eye Institute (NIH) |
Social Security |
| Defines visual impairment including blindness as "an impairment in vision that, even with correction, adversely affects a child's educational performance. The term includes both partial sight and blindness. [§300.8 (c)(13)] |
Classifies visual impairment into distance (mild, moderate, severe, and blindness) and near. |
Defines visual impairment as visual activity of 20/40 or worse in the better-seeing eye with correction, excluding blindness. Whereas, blindness is defined as visual acuity of 20/200 or worse in the better seeing eye with correction. Both low vision and blindness are included in the category "All Visual Impairmnet". |
Visual acuity measured between 20/100 and 20/200, with the inability to read any of the letters on the 20/100 line, is determined to statutory blindness based on visual acuity of 20/200 or less. Visual field loss equal to or less than 20 degrees diameter. [2.00(5b)] |
Resources
For more information about visual impairment please refer to the PaTTAN publication “Teacher’s Desk Reference: Visual Impairment." This publication provides:
- Overview of visual impairment
- A description of the unique needs of students with visual impairments
- Information about the primary support services available for students with visual impairments
- Comparison of the general education teacher and the teacher of students with visual impairments responsibilities
- Information on orientation and mobility (O&M) and O&M specialists
- Introduction to assistive technology
- Tips for teachers
Learn about educational visual impairment eligibility