define myopia and hypeermetropia in 5 points
Answers
Answer:
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.
Explanation:
MYOPIAHYPERMETROPIAMyopia is also called as Near-sightedness.Hypermetropia is called as Far-sightedness. NATUREIn Myopia, the person can see nearby objects, but cannot see far objects clearly.In Hypermetropia, the person can see far objects clearly, but cannot see near objects clearly. IMAGEIn people with myopia, the image is formed in front of retina in the eye.In people with hypermetropia, the image is formed behind the retina in the eye. EYE-BALLThe size of the eye-ball increases in the myopic people.The size of the eye-ball decreases in the hypermetropic people. FOCAL LENGTHIn myopia, the focal length of the eye lens decreases.In hypermetropia, the focal length of the eye lens increases. CORRECTED USINGMyopia can be corrected using Double-Concave lens.Hypermetropia is corrected using the Double-Convex lens. LENSTo correct myopia, we need to select a lens which forms an image at the far point for an object at infinity.To correct hypermetropia, we need to use lens which forms an image of an object beyond near point when an object is placed between near point and least distance of clear vision
Answer:
Myopia:
1) Near sightedness
2) elongation of eye ball
3) excessive curvature of eye lens
4) focal length of eye lens become too short
5) image is formed front of retina
Hypermetropia:
1)Far sightedness
2) eye ball becomes too small
3) curvature of eye lens become too short
4) focal length becomes too long
5) image formed behind the retina
Hope it helps you