In: Biology
What does visual acuity of 20/20 mean? What does 20/40 mean?
Q . What does visual acuity of 20/20 means ?
Ans - Visual acuity of 20/20 is a term used to express the clarity & sharpness of the vision ( normal visual acuity ) at a distance of 20 feet . If a person have 20/20 vision it means that person can clearly see the object at 20 feet which should normally clearly can be seen . A person having 20/20 vision does not mean that the person perfect vision . It only determines the clarity & sharpness of the vision at a distance of 20 feet . Overall , 20/20 vision is not a razor sharp vision .
Q . What does 20/40 means ?
Ans- A person having 20/40 vision is slightly nearsighted & may or may not need contact lenses & eyeglasses . 20/40 vision is a term used to express that the person with 20/40 vision will see the object at 20 feet what a person with normal vision sees at 40 feet . Another way to say this is for , a person with 20/40 vision , the object must be at the half of the normal distance for the person to see the objects .