It's not a functional low vision definition and doesn't tell us very much at all about what a person can and cannot see. 'Legal blindness' is a definition used by the United States government to determine eligibility for vocational training, rehabilitation, schooling, disability benefits, low vision devices, and tax exemption programs. You can learn more about these specialized eye charts and testing procedures at What is a Low Vision Examination?

If you have low vision, it is necessary to have a different kind of eye examination that uses different and more detailed tests to determine what you can and cannot see.

Most eye care professionals prefer to use the term 'low vision' to describe permanently reduced vision that cannot be corrected with regular glasses, contact lenses, medicine, or surgery.

In other words, low vision is 'not enough vision to do whatever it is you need to do,' which can vary from person to person.It is better defined in terms of function, rather than test results. Low vision is uncorrectable vision loss that interferes with daily activities.Here's another - more functional - definition of low vision: Not all eye care professionals agree with an exclusively numerical (or visual acuity) description of low vision. Please note: An actual Snellen Eye Chart is much larger than the one depicted here therefore, it's not recommended that you use this chart to test your own (or a friend's or family member's) visual acuity. If the smallest print you can read is line 3 (T O Z) from 20 feet away while wearing your regular glasses or contact lenses, the doctor records your vision (or visual acuity) as 20/70 with best correction. If you can read line 8 (D E F P O T E C) from 20 feet away while wearing your regular glasses or contact lenses, the doctor records your vision (or visual acuity) as 20/20 with best correction. Your eye doctor will ask you to read or identify each line or row at a fixed distance (usually 20 feet), although a 10-foot testing distance is also used. It contains rows of letters, numbers, or symbols printed in standardized graded sizes. In the United States, the Snellen Eye Chart (pictured at left) is a test that ophthalmologists and optometrists use to measure a person's distance visual acuity. A visual acuity measurement of 20/70 means that a person with 20/70 vision who is 20 feet from an eye chart sees what a person with unimpaired (or 20/20) vision can see from 70 feet away.Дў0/70 can best be understood by examining a standard eye testing chart that you may have used in your own doctor's office during an eye examination. Visual acuity is a number that indicates the sharpness or clarity of vision. Low vision is a condition caused by eye disease, in which visual acuity is 20/70 or poorer in the better-seeing eye and cannot be corrected or improved with regular eyeglasses.Here is one definition of low vision, related to visual acuity:

Those descriptions are no longer in general use, however. You may have heard the terms 'partial sight' or 'partial blindness' or even 'poor vision' also used to describe low vision. Most surveys and studies indicate that the majority of people in the United States with vision loss are adults who are not totally blind instead, they have what is referred to as low vision. If you value the information you've found on our site, please make a gift today! This work is only possible because of donations from people like you. Throughout 2020, we've researched the impact of COVID-19 on people who are blind or have low vision, and advocated for meaningful responses to the pandemic. Most of our funding comes from individuals like you. Using Low Vision Optical and Non-Optical Devices

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