Question

(a) List three common refractive defects of vision. Suggest the way of correcting these defects. (b) About 45 lac people in the developing countries are suffering from corneal blindness. About 30 lac children below the age of 12 years suffering from this defect can be cured by replacing the defective cornea with the cornea of a donated eye. How and why can students of your age involve themselves to create awareness about this fact among people?

Answer 1

The 3 common defects are :- 
# ) Myopia
# ) Hypermetropia
# ) Presbyopia.

Corrections:-

#) Myopia- Concave Lens
#) Hypermetropia - Convex lens
#) Presbyopia - Bifocal lens of corrective focal length.

By having Awareness classes or by programmes.
By printing a pamphlet 
By making posters

Thank you.....!!!!
Mark as brainliest of helpful..
Yours, Jahnavi

Answer 2

Answer:

1)Myopia it can be corrected by the help of diverging lens or concave lens .It generally develops in childhood or teens (between 8 & 14)

2)Hypermetroia it can be corrected by the help of converging lens or convex lens .

3) Presbyopia It can be corrected by the help of bifocal lens .It generally develops after the age of 40 years

4) Astigmatism It can be corrected by the help of cylindrical lens.

Astigmatism can start in childhood or in adulthood