Final answer:
The power of the tear layer in contact lenses can be calculated by subtracting the power of the lens from the power of the eye. In the case of a mildly farsighted person with a contact lens prescription of 0.750 D and a near point of 29.0 cm, the power of the tear layer is 0.750 D.
Step-by-step explanation:
The tear layer between the cornea and the lens in contact lenses can affect the power of the lens correction. The power of the tear layer can be calculated by using the formula:
Power of tear layer = Power of lens - Power of eye
For example, in the case of a mildly farsighted person with a contact lens prescription of 0.750 D and a near point of 29.0 cm, if the correction is ideal, the power of the tear layer can be calculated as:
Power of tear layer = 0.750 D - 0 D (since a farsighted person's eye has a power of 0 D)
This means that the power of the tear layer is 0.750 D.