Final answer:
The medical term for "crossed eyes" is Strabismus (A), a condition where the eyes are misaligned and do not work in unison.
Step-by-step explanation:
The medical term commonly known as "crossed eyes" is Strabismus (A). This condition involves the misalignment of the eyes, which can point in different directions and fail to work together. Strabismus can be caused by issues with the muscles, nerves, or signaling pathways in the brain that control eye movements.
Contrarily, Myopia (B) refers to nearsightedness, where distant objects appear blurry; Presbyopia (C) is an age-related condition causing difficulty focusing on close objects; and Astigmatism (D) is characterized by uneven focus of the eye, caused by irregularities in the shape of the cornea or lens.