A man can see the object between 15 cm and 30 cm. He uses the lens to see the far objects. Then due to the lens used, the near point is at ____.
30 cm
15 cm
The far point of a myopia eye is at 40 cm. For removing this defect, the power of lens required is ____.
40 D
– 4 D
– 2.5 D
0.25 D
A man suffering from myopia can read a book placed at 10 cm distance. For reading the book at a distance of 60 cm with relaxed vision, focal length of the lens required is ____.
45 cm
– 20 cm
– 12 cm
30 cm
If the distance of the far point for a myopia patient is doubled, the focal length of the lens required to cure it is come ____.
half
double
the same but a convex lens
the same but a concave lens
A Presbyopia patient has near point as 30 cm and far point as 40 cm. The dioptric power for the corrective lens for seeing distant objects is ____.
40 D
4 D
– 2.5 D
0.25 D
An imaginary line joining the optical centre of the eye lens and the yellow point is called as ____.
principal axis
vision axis
neutral axis
optical axis
The light when enters the human eye experiences most of the refraction while passing through ____.
Cornea
Aqueous humour
Vitreous humour
Crystalline lens
The impact of an image on the retina remains for ____.
0.1 s
0.5 s
10 s
15 s
A person is suffering from myopic defect. He is able to see clear objects placed at 15 cm. What type and of what focal length of lens he should use to see clearly the object placed 60 cm
Away?
Concave lens of 20 cm focal length
Convex lens of 20 cm focal length
Concave lens of 12 cm focal length
Convex lens of 12 cm focal length
The sensation of vision in the retina is carried to the brain by ____.
cilliary muscles
blind spot
cylindrical lens
optic nerve