Many people seek to understand the difference between blindness and being “legally blind.” The term “legally blind” serves as a specific threshold for visual impairment recognized by law, often to determine eligibility for benefits, insurance, or access to specialized programs. It’s important to understand that legal blindness is not always the same as total blindness, and the definition is more nuanced than many assume.
Defining Legal Blindness: Visual Acuity and Field of Vision
The key criterion for being legally blind is based on visual acuity, which is the sharpness of your vision. Specifically, legal blindness is defined as having vision no better than 20/200 in your best eye with the best possible correction, such as eyeglasses or contact lenses.
To understand 20/200 vision, consider the standard eye chart, known as a Snellen chart. The large “E” at the top represents 20/200 vision. If you can only see this large “E” even with corrective lenses when standing 20 feet away from the chart, while someone with normal vision can see letters 10 times smaller at the same distance, you meet one part of the criteria for legal blindness.
It’s important to note: The Snellen chart is a common tool used by eye doctors to measure visual acuity and determine if a person meets the criteria for legal blindness.*
Legal blindness can also be determined by visual field restriction. This refers to the breadth of what you can see peripherally. If your visual field is 20 degrees or less in your widest diameter in your better eye, this also qualifies as legal blindness, even if your central visual acuity is better than 20/200. Imagine looking through a narrow tunnel – that constricted field of vision significantly impacts daily life and can lead to a legal blindness diagnosis.
Legal Blindness vs. Complete Blindness: The Spectrum of Vision
A common misconception is that all blind people see nothing at all, or only darkness. In reality, blindness exists on a spectrum. Legal blindness does not necessarily mean total blindness. Many individuals who are legally blind have some degree of sight. They might be able to perceive light, shadows, movement, or even some colors and shapes.
The term “legally blind” is therefore a functional definition, not a description of complete darkness. It acknowledges a level of vision loss that significantly impacts a person’s ability to perform everyday tasks, such as driving, reading standard print, or navigating unfamiliar environments, even with corrective eyewear.
Why Does the “Legally Blind” Definition Matter?
Understanding “What Is Legally Blind” is crucial because it opens the door to various forms of support and resources. This legal classification can enable access to:
- Government benefits: Such as Social Security benefits or disability allowances.
- Tax exemptions: Certain tax benefits may be available for those who are legally blind.
- Vocational rehabilitation services: Programs designed to help legally blind individuals gain employment and independence.
- Assistive technology and devices: Access to tools and technologies that can aid in daily living and improve quality of life.
- Programs for the blind and visually impaired: Eligibility for specialized services, training, and support networks.
If you are concerned about your vision and think you might meet the criteria for legal blindness, it is essential to consult with an eye doctor. A comprehensive eye exam can accurately assess your visual acuity and field of vision, providing you with a clear understanding of your vision status and guiding you toward appropriate resources and support if needed. Regular eye exams are crucial for everyone to monitor vision health and address any concerns promptly.
