26.2 Vision Correction

Which of the following types of light have a wavelength greater than that of visible light?

1. gamma rays
2. infrared
3. radio
4. ultraviolet

1. I, II, and III
2. I and IV only
3. II and III only
4. III only

What is the far point of a person whose eyes have a relaxed power of 50.5 D?

(a) A laser vision correction reshaping the cornea of a myopic patient reduces the power of his eye by 9.00 D, with a $\pm 5 . 0$ uncertainty in the final correction. What is the range of diopters for spectacle lenses that this person might need after LASIK procedure? (b) Was the person nearsighted or farsighted before the procedure? How do you know?

What was the previous far point of a patient who had laser vision correction that reduced the power of her eye by 7.00 D, producing normal distant vision for her?

A student’s eyes, while reading the blackboard, have a power of 51.0 D. How far is the board from his eyes?

A young woman with normal distant vision has a 10.0% ability to accommodate (that is, increase) the power of her eyes. What is the closest object she can see clearly?

A very myopic man has a far point of 20.0 cm. What power contact lens (when on the eye) will correct his distant vision?

A myopic person sees that their contact lens prescription is $–4.00 D$. What is their far point?

The contact lens prescription for a mildly farsighted person is 0.750 D, and the person has a near point of 29.0 cm. What is the power of the tear layer between the cornea and the lens if the correction is ideal, taking the tear layer into account?

A teacher sees that a child’s contact lens prescription is 0.750 D. What is the child’s near point?

The contact lens prescription for a nearsighted person is $–4.00 D$ and the person has a far point of 22.5 cm. What is the power of the tear layer between the cornea and the lens if the correction is ideal, taking the tear layer into account?