the eye topic questions

Question 1

Describe how light rays are focused to give normal vision(2)

Answer 1

light rays are refactred(1)
Light rays focus on the retina(1)

Question 2

Describe the causes of shortsightedness and longsightedness.(6)

Answer 2

With shortsightedness light rays are focused infront of the retina and the cornea refracts light rays too much.The cornea is too convex.

With longsightedness lights rays are focused behind the retina and the lens dosent refract enough. The eyeball is too short.

Question 3

Explain how a diverging lens corrects short sightedness(2)

Answer 3

Diverging lens refracts light rays outwards(1)
so light rays meet on retina(1)

Question 4

Explain how cataracts are usually treated(2)

Answer 4

surgery/removing the lens(1)
replace with plastic lens(1)

Question 5

Explain how the size of pupil of the eye changes when a torch is shown into the eye of the person(2)

Answer 5

pupil gets smaller(1)iris(1)gets bigger(1)

Question 6

Explain why this person cannot see distant objects and how it can be corrected(6)

Answer 6

Why distant objects cannot be seen clearly
person is shortsighted
Light is not focused on retina
eyeball is too long
lens cannot be made thin enough so the light is refracted too much

how the problem can be corrected

go to opticians
glasses lenses need to be concave

Question 7

Explain why the picture seen through eyes with cataracts is less clear(2)

Answer 7

lens form a cloudy patch(1)
less light reaches retina(1)

Question 8

which structure of the eye contains light receptor cells(1)

Answer 8

retina(1)