How do you correct the eye defect Myopia ?

Explanation

1) Some people cannot see objects at long distances but can see nearby objects clearly. This type of defect in vision is called 'Near sightedness'.
2) Myopia is corrected by using a concave lens of focal length equal to the distance of the far point F from the eye.
3) This lens diverges the parallel rays from distant object as if they are coming from the far point.
4) Finally the eye lens forms a clear image at the retina.
5) Here object distance (u) is infinity and image distance (v) is equal to the far point. `u=-oo`, v=distance of far point =-D, f=focal length of bi-concave lens.
We know `(1)/(f)=(1)/(v)-(1)/(u) implies (1)/(f)=-(1)/(D)impliesf=-D`
Here 'f' is negative showing that it is a concave lens.