Which statement best captures the general principle of prism correction for diplopia in strabismus?

Which statement best captures the general principle of prism correction for diplopia in strabismus?

• A. Prisms displace the image to align the eyes with the patient’s fusion capacity, reducing or eliminating diplopia.
• B. Prisms permanently realign the eyes by altering extraocular muscle function.
• C. Prisms cure underlying nerve palsies by improving nerve conduction.
• D. Prisms are used to change the size of the pupil to reduce diplopia.

Answer: (A)

Prisms correct diplopia by shifting the image seen by one eye so that the two images fall on corresponding retinal points that the brain can fuse. This optical displacement uses the brain’s binocular fusion mechanism to merge the two eyes’ images into a single percept, provided the deviation is within the patient’s fusion range. Prisms do not move the eyes themselves or repair underlying muscle or nerve problems, nor do they change pupil size. They are a reversible optical aid that relies on the patient’s fusion capacity to reduce or eliminate double vision.

Prisms correct diplopia by shifting the image seen by one eye so that the two images fall on corresponding retinal points that the brain can fuse. This optical displacement uses the brain’s binocular fusion mechanism to merge the two eyes’ images into a single percept, provided the deviation is within the patient’s fusion range. Prisms do not move the eyes themselves or repair underlying muscle or nerve problems, nor do they change pupil size. They are a reversible optical aid that relies on the patient’s fusion capacity to reduce or eliminate double vision.