This change was made as newer studies showed that best-corrected vision overlooks a larger proportion of the population who has visual impairment due to uncorrected refractive errors, and/or lack of access to medical or surgical treatment.Distance vision impairment:

Category 0: No or mild visual impairment –presenting visual acuity better than 6/18
Category 1: Moderate visual impairment –presenting visual acuity worse than 6/18 and better than 6/60
Category 2: Severe visual impairment –presenting visual acuity worse than 6/60 and better than 3/60
Category 3: Blindness –presenting visual acuity worse than 3/60 and better than 1/60
Category 4: Blindness—presenting visual acuity worse than 1/60 with light perception
Category 5: Blindness—irreversible blindness with no light perceptionNear vision impairment:

Near visual acuity worse than N6 or M.08 at 40 cm. United Kingdom
Severely sight impaired

Defined as having central visual acuity of less than 3/60 with normal fields of vision, or gross visual field restriction. Unable to see at 3 metres (10 ft) what the normally sighted person sees at 60 metres (200 ft).Sight impaired

Able to see at 3 metres (10 ft), but not at 6 metres (20 ft), what the normally sighted person sees at 60 metres (200 ft)
Less severe visual impairment is not captured by registration data, and its prevalence is difficult to quantifyLow vision

A visual acuity of less than 6/18 but greater than 3/60. Not eligible to drive and may have difficulty recognising faces across a street, watching television, or choosing clean, unstained, co-ordinated clothing.In the UK, the Certificate of Vision Impairment (CVI) is used to certify patients as severely sight impaired or sight impaired.
Blindness, in this sense, is used both metaphorically (to refer to someone who was ignorant but later became knowledgeable) and literally, as a reference to those healed in the Bible. In the later years of his life, Newton himself would go blind. H. G. Wells story "The Country of the Blind" explores what would happen if a sighted man found himself trapped in a country of blind people to emphasise societys attitude to blind people by turning the situation on its head. Bob Dylans anti-war song "Blowin in the Wind" twice alludes to metaphorical blindness: How many times can a man turn his head // and pretend that he just doesnt see... How many times must a man look up // Before he can see the sky? Contemporary fiction contains numerous well-known blind characters. Some of these characters can see by means of devices, such as the Marvel Comics superhero Daredevil, who can see via his super-human hearing acuity, or Star Treks Geordi La Forge, who can see with the aid of a VISOR, a fictional device that transmits optical signals to his brain. Sports
Blind and partially sighted people participate in sports, such as swimming, snow skiing and athletics. Some sports have been invented or adapted for the blind, such as goalball, association football, cricket, golf, tennis, bowling, and beep baseball. The worldwide authority on sports for the blind is the International Blind Sports Federation. People with vision impairments have participated in the Paralympic Games since the 1976 Toronto summer Paralympics.