What are the requirements to be legally blind?

The legal definition of blindness varies country to country, however, it generally refers to a level of vision impairment that meets certain specific criteria. For some it is measured by the level of visual acuity, which measures how well a person can see at a specific distance. In most cases, if a person has visual acuity of 20/200 or less in the better eye, even with corrective lenses, they'll be considered legally blind. Visual field loss is also a factor in determining legal blindness, where an individual's field of vision at certain angles is limited to less than 20 degrees.

It's important to note that legal blindness does not mean complete loss of vision. Individuals who are legally blind may still have some remaining sight and may be able to perceive light, colors, or shapes, but their vision is severely impaired and falls within the parameters set by the legal definition.