WHO definition of blindness
Legal blindness Is defined as visual acuity (vision) of 3/60 or less in the better eye with best correction possible In many areas, people with average acuity who nonetheless have a visual field of less than 10 degrees (the norm being 180 degrees) are also classified as being legally blind Ref: New Guidelines, NPCB, GOI 2017-18
<6/60
<3/60
<6/18
<6/9
Non communicable diseases