Question

distinguish between myopia and hypermetropia show with the help of suitable diagram how this defect can be correct

Answer 1

MYOPIA

Myopia is a condition in which the people cannot see objects which are beyond the ‘far point’. Far Point is the point of maximum distance at which the eye lens can form an image on the retina. Myopia is also called as’Near- Sightedness’, in which person cannot see the far objects clearly but can see the near objects clearly. The Myopia can be corrected using Double-Concave lens.

EXAMPLE: A student who is unable to see the letters on the classroom board is suffering with Myopia.

HYPERMETROPIA

Hypermetropia is a condition in which the people cannot see objects placed between the ‘Near point’ and the point of least distance of distinct vision. ‘Near Point’ is the point of minimum distance at which the eye forms clear image on retina. Hypermetropia is also called as ‘Far-Sightedness’ because the individual cannot be able to see the near objects clearly, but can see the far objects clearly. The Hypermetropia is corrected using the Double- Convex lens.

Correction of myopia Ray diagram!

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Answer 2

myopia is short sightedness, the image is formed in front of the retina due to the elongation of the eye ball or due to decrease in focal length
correction concave lense with suitable focal length


hypermetropia means long sightedness ,the image is formed behind the retina It can be due to shortening of eye ball or increase in focal length
it can be corrected by convex lense of suitable focal lenght