Question

The power for normal close vision is 54.0 D. In a vision-correction procedure, the power of a patient’s eye is increased by 3.00 D. Assuming that this produces normal close vision, what was the patient’s near point before the procedure?

Answer 1

The patient's near point before a vision-correction procedure that increased their eye's power by 3.00 D was approximately 19.6 cm. This was calculated using the lens formula where the new power for normal close vision is taken as 54.0 D and the original power was 51.0 D.

Step-by-step explanation:

The power required for normal close vision is typically considered to be 54.0 D (diopters). When a vision-correction procedure such as LASIK increases the power of a patient’s eye by 3.00 D, assuming it brings their close vision to normal levels, we can determine the patient’s near point before the procedure.

To find the original near point, we use the lens formula:

1/f = P

where f is the focal length in meters, and P is the power in diopters.

The patient’s power before the procedure was 54.0 D – 3.00 D = 51.0 D. The focal length corresponding to 51.0 D is:

1/f = 51.0 D

f = 1/51.0 meters

f ≈ 0.0196 meters, or ≈ 19.6 cm

This means the patient’s near point was approximately 19.6 cm before the procedure.