A. Convex
B. Concave
C. Bifocal
D. Cylindrical
Submitted by: Aamir Hussain Laghari
In Presbyopia defect both near and far object are not clearly visible i.e., far point is lesser than infinity and near point greater than 25 cm. This can be removed either by using two separate spectacles one for myopia and other for hypermetropia or by using bifocal lens. It is an old age disease. At old age ciliary muscles lose their elasticity so they can not change the focal length of eye lens effectively and eye losses its power of accommodation.
