Difference between Correction of myopia and hypermetropia

Difference between Correction of myopia and hypermetropia

Correction of myopia

1) The defect in human eye in which one can see nearby objects clearly, but cannot see distinct object clearly is known as myopia or near sightedness.

2) To correct this defect, an ophthalmic doctor prescribes the concave lens of suitable power (or focal length) to use in spectacles.

3) Hence the power of lens for the person with myopia is negative.

4) Defective eye of person suffering with myopia is shown below, in which we can see that ciliary muscles have expands the lens, but doesn’t relaxed, so that the focal length of eye lens decreases, eyeball gets elongated.

5) After using concave lens of suitable focal length, the structure of corrected eye will appear as follows,

Correction of Hypermetropia

1) The defect in human eye in which one can see distinct objects clearly, but cannot see nearby object clearly is known as hypermetropia or far sightedness.

2) To correct this defect, an ophthalmic doctor prescribes the convex lens of suitable power (or focal length) to use in spectacles.

3) Hence the power of lens for the person with hypermetropia is positive.

4) Defective eye of person suffering with hypermetropia is shown below, in which we can see that ciliary muscles have contracts the lens, but doesn’t relaxed, so that the focal length of eye lens increases, eyeball gets flattered.

5) After using concave lens of suitable focal length, the structure of corrected eye will appear as follows,

Updated: September 30, 2021 — 11:45 am

Leave a Reply

Your email address will not be published. Required fields are marked *