Question

Which type of lens is used to correct astigmatism?

Answer 1

Hint: In this question firstly we will write the definition of astigmatism and study about its causes, symptoms, diagnosis and treatment. During this we will get to know about which type of lens is used to correct astigmatism.

Complete step by step answer:
Astigmatism is basically an eye disease or an eye problem in which our eye isn’t completely round. Almost every one of us has this to some degree. It is basically a reflective error. How an eye focuses on light is astigmatism. Its correction can be done easily with contact lenses, eyeglasses or refractive surgery. Astigmatism can happen with nearsightedness or myopia and farsightedness or hypermetropia.

Symptoms of astigmatism:
i) Eyestrain
ii) Blurriness or distorted version
iii) Headaches
iv) Difficulty seeing at night.

Causes:
a) It can be caused by birth.
b) It can be caused after an accident or an eye injury, eye disease, or by surgery.
c) It can also be caused by keratoconus which clears your cornea i.e. front part of your eye thinner or more cone-shaped.

Diagnosis:
A) Our eyes can be affected by astigmatism slowly. We should consult an eye doctor if we see any changes in our eye or change in vision.
B) A complete eye exam or eye test is conducted by the eye doctors. They can ask you to read an eye chart.
C) They can use various tools to measure your vision.
To correct the problem of astigmatism a cylindrical lens power is used. It is used to correct the difference between the powers of the two principal meridians of the eye. So, it can be removed by using a lens which is cylindrical.

Note: Astigmatism is not caused by reading or watching something in low light or sitting very close to any of the screens like TV, laptops, phones, etc. We have discussed the causes above. Irregular curvature of the eye’s cornea can cause astigmatism. The way of light passes is changed due to astigmatism.