Question

What was the original far point of a patient who had laser vision correction to reduce the minimum power of her eye by 4.74 diopters, producing normal distant vision for her? assume a distance from the eye lens to retina of 2 cm so the minimum power for normal vision is 50 diopters.

Answer 1

The original far point of the patient's eye was 18.3 cm, which was calculated using the lens formula and the previous eye power of 54.74 diopters before the laser vision correction that resulted in normal distant vision.

Step-by-step explanation:

Calculating the Original Far Point After Laser Vision Correction

The question concerns the original far point of a patient who underwent laser vision correction. Initially, the patient had a minimum power of her eye that was 4.74 diopters higher than after the procedure, given that post-operation, the patient achieved normal distant vision which has a power of 50 diopters. To find the original far point, we can calculate the previous power of the eye and use the lens formula.

The previous power of the eye was 50 + 4.74 = 54.74 diopters. The lens formula is 1/f = P, where f is the focal length in meters and P is the power in diopters. Therefore, the original far point of the eye, which is the maximum distance at which objects are seen clearly without accommodation, is equivalent to the focal length of the eye's lens before the surgery.

By rearranging the formula to f = 1/P, and substituting the known power, we get f = 1/54.74 diopters = 0.0183 meters or 18.3 cm. Hence, the original far point was 18.3 cm before the laser vision correction.