Final answer:
Anisocoria is the term for the presence of different sizes of a patient's pupils. It can be related to conditions like bilateral hemianopia or astigmatism, which are vision defects caused by issues such as compression of the optic chiasm or irregularities in the shape of the cornea.
Step-by-step explanation:
The term for the presence of different sizes of a patient's pupils is anisocoria. Anisocoria can be benign or indicative of a more serious medical condition, such as pressure on the optic nerves. It is important to consider anisocoria in the context of other symptoms, such as the loss of lateral peripheral vision known as bilateral hemianopia, which may suggest a pathological cause like the compression of the optic chiasm by a pituitary growth, rather than within the visual system itself. Understanding how pupils react to light can further aid in diagnosing a range of vision problems, including astigmatism, which is rooted in the unevenness of the eye's focus.