Final answer:
Patients with congenital deviations in eye alignment, like strabismus, often experience diplopia, where they see double images. This statement is generally true.
Step-by-step explanation:
A patient who has a congenital deviation in vision may often experience diplopia, which is the perception of two images from a single object. The statement, "A patient who has a congenital deviation often are diplopic" can be true depending on the specific condition affecting the patient. For instance, congenital strabismus, a condition where the eyes do not properly align with each other, can cause diplopia. Those with the condition may have difficulty with depth perception and seeing objects as single, cohesive images.