Correcting sight problems

Question 1

how can you correct eye conditions

Answer 1

spectacle are a simple way. glasses

Question 2

how do glasses correct long sightedness

Answer 2

a covering lens brings the rays together so light is focused on eh retina

Question 3

how do glasses correct short sightedness

Answer 3

a diverging lens makes the rays come together further away, so light is focused on the retina.

Question 4

state some advantages and disadvantages of wearing contact lenses

Answer 4

A: safe when playing sport because they cannot be knocked off or broken, people may not prefer to wear glasses
D: must be kept very clean otherwise they can cause eye infection; some people find them uncomfortable to wear

Question 5

explain how laser treatment is used to correct problems like long and short sightedness

Answer 5

patient is given a local anaesthetic. lasers are used to make small, precise cuts in the cornea. these permanently change the shape of the cornea. shaping the cornea in this way can make it act like a diverging or converging lens, as required by the patients condition