Which statement best describes strabismus?

• A. A rapid, searching movement of the eyeballs
• B. Associated with visual and/or neurological abnormalities
• C. Results from muscular incoordination and gives the appearance of cross eyes
• D. Causes refractive error only

Answer: (C)

Strabismus is a misalignment of the eyes caused by imbalanced or poorly coordinated extraocular muscles. This results in one eye deviating relative to the other, producing the classic appearance of cross-eyed. The defining feature is the ocular misalignment from muscular/inneuromuscular control issues, not a rapid eye movement or merely an association with other conditions.

Nystagmus describes rapid, bouncing or searching eye movements, which is a different phenomenon. While strabismus can be seen with visual or neurologic abnormalities, that association doesn’t define it—the core issue is the misalignment itself. Refractive error can play a role in some cases (like accommodative strabismus) but strabismus is not caused by refractive error alone.