Final answer:
Surgical destruction of the crystalline lens is called phacolysis. It is often performed to treat cataracts, resulting in a need for high-power spectacle lenses of about 16 D after surgery. Presbyopia, on the other hand, is the age-related loss of accommodation, corrected with converging lenses. The correct option is a).
Step-by-step explanation:
Surgical destruction of the crystalline lens is called phacolysis. This procedure is typically performed to treat cataracts, which are characterized by cloudiness in the lens of the eye. Cataracts can cause light to be dispersed or diffused, leading to blurred vision.
After the removal of the crystalline lens, a high-power spectacle lens is often prescribed to focus light properly onto the retina since the natural lens is missing. A typical power for such a spectacle lens would be about 16 diopters (D).
Presbyopia refers to the loss of the eye's ability to accommodate, or focus on close objects, due to aging. It is corrected by the use of a converging lens to add power for close vision. However, presbyopia is not related to the surgical destruction of the crystalline lens.
Orthoptics is a field concerned with the treatment of disorders of eye movements and related vision problems, but it does not refer to a surgical procedure.
Finally, phacosclerosis refers to the hardening of the lens, which is also not directly related to its surgical destruction. Option a) is the correct one.