Explain the Myopia using the diagram.

1.	Explain the Myopia using the diagram.
Answer» Solution :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.

Discussion