Question

Many people wear glasses to compensate for the fact that the optical system of their eye does not focus a sharp image on the retinas. Discuss at least three of the disorders of focusing. Be sure that you are discussing the complete epigenetic origin which should include a discussion of the genetic/biological origin and the environmental influence related to these disorders of focusing. Include the impact of culture in the development of the optical system at various stages of the lifespan.

Answer 1

Disorders of focussing are.....1. Myopia which is a condition ( refractory error) in which the light rays fall infront of retina thus the far objects cannot be seen clearly that is they look blurry.

2.... Hypermetropia ....in this nearby objects look blurry and unclear...it arises because the light rays fall behind the retina for which glasses are used to focus the light rays on retina

3.. Astigmatism is also a focusing disorder in which the nearby objects and far away objects appear distorted or blurry...

4.... strabismus ...it is a condition in which eyes get deviated and fail to focus the light rays properly on retina...it is of 3 types esotropia,exotropia and hypertropia ...

Due to these type of disorders ,common symptom s like headache, eyestrain, double vision, squinting , difficult in focusing while reading or writing..arises....thus these conditions must be treated either using glasses or by surgery.

Major cause of refractory errors is eyeball length ,,, problems with shape of cornea,,,,and aging of lens which may lead to cataract...