The definition of legally blind is a crucial factor in determining eligibility for various support programs, such as vocational training, schooling, and tax exemptions in the United States.
According to the American Foundation for the Blind (AFB) and the Centers for Disease Control and Prevention (CDC), one is considered legally blind if their visual acuity is 20/200 or less in their better-seeing eye with the best possible correction. This means that, even when wearing regular glasses or contact lenses, a person with 20/200 visual acuity can only see at 20 feet away what someone with perfect (20/20) vision can see from 200 feet away.
Importantly, legal blindness does not necessarily indicate total sightlessness. Individuals with low vision, or visual acuity worse than 20/100, may still have some functional sight but experience difficulties with daily tasks without specialized assistance or alternative methods.
The Snellen Eye Chart is a standard tool used by eye care professionals to measure visual acuity and determine whether someone meets the criteria for legal blindness.
What does 20/400 Mean?
Having 20/400 vision means that an individual can only see clearly at a distance of 20 feet, while someone with normal vision can see the same object clearly from 400 feet away.
This level of visual acuity is considered to have very low functional vision, and can significantly hinder one’s ability to perform everyday tasks without the assistance of specialized tools, low vision aids, or services.
It is important to note that 20/400 vision is much worse than 20/100 and 20/200 vision, with the latter being the threshold for legal blindness in the United States, which means that an individual can only see clearly at a distance of 20 feet, but those with normal vision can see at 200 feet.
Individuals with 20/400 vision are encouraged to consult an eye care professional to better understand their visual acuity and explore potential solutions to improve their functional vision and overall quality of life.
What does 20/200 Mean?
The term “20/200 vision” refers to the clarity of an individual’s eyesight at a distance of 20 feet. This means that a person needs to be 20 feet away from an object to see it as clearly as someone with standard vision can see it from 200 feet away.
Visual acuity of 20/70 or worse is considered low vision, which impacts daily activities and functionality. For people with 20/200 vision or worse, even with corrective lenses, they may be diagnosed as legally blind.
Having 20/200 vision can impede general activities and may result in the need for specialized tools or aids for daily life. Regular eye examinations are crucial for early detection and management of any vision issues.
If you suspect that you have 20/200 vision or any other visual impairment, it is important to consult with an eye care professional for a comprehensive eye exam and advice on available corrective measures.
What does 20/100 Mean?
A normal visual acuity is 20/20; whereas, 20/100 vision indicates that you have low vision.
Having 20/100 vision means you must stand no more than 20 feet away from an object to see it clearly. In contrast, someone with normal vision can see the same object clearly from 100 feet away.
Various factors can lead to low vision, including refractive errors, astigmatism, and eye diseases.
As the numbers increase (e.g. 20/200 and 20/400), it means that you have severe vision loss, and your functional vision becomes poorer. The higher the number, the greater the distance you need to be from an object to see it clearly.
If you have 20/100 vision, you may need to wear eyeglasses to improve your visual acuity. Seeing an eye expert for a low vision exam is essential to determine the extent of your vision problem and to recommend optical and non-optical devices to help with low vision. Depending on your specific needs, your eye doctor might suggest reading glasses, magnifying lenses, or specialized lighting systems.
What is the Difference Between the 20/100, 20/200, and 20/400?
The terms 20/100, 20/200, and 20/400 are used to denote different levels of visual acuity, which is the sharpness and clarity of vision at a specific distance, generally measured at 20 feet. These numbers provide a comparison between an individual’s vision and the average person with normal vision, which is typically 20/20.
In the case of 20/100 vision, it means that an individual can perceive an object clearly from 20 feet away, whereas someone with normal vision can perceive the same object clearly from 100 feet away. This level of vision is considered low, and may require corrective eyeglasses to enhance clarity and sharpness.
20/200 vision signifies a more severe visual impairment, where an individual can only see an object clearly at 20 feet, while someone with normal vision can see it clearly from 200 feet away. This level of visual acuity is classified as legally blind in the United States.
Lastly, 20/400 vision implies that an individual must be 20 feet away from an object in order to see it clearly, whereas a person with normal vision can see the same object with clarity at 400 feet away. This level of visual acuity denotes profound vision loss, making it extremely difficult to carry out daily tasks without assistance.
