A 15 year-old emmetropic boy has an amplitude of accommodatio of 30 D.

a. What is his range of accommodation?

Another 20 year-old man has a +10 D hypermetropia with a 20 D amplitude of accommodation.

b. what is his near point and the range of accommodation when he is not wearing the spectacle correction?

c. What is his near point and the range of accommodation when he is wearing his +10.00 dioptres?