To be considered amblyogenic, strabismus must be constant and unilateral.

• A. True
• B. False
• C. Sometimes
• D. Not specified

Answer: (A)

Amblyopia from strabismus occurs when the visual system is developing and one eye is persistently misaligned, leading the brain to suppress that eye’s input to avoid double vision. When the deviation is constant and unilateral, this suppression becomes sustained, so the nonfused image never develops normal visual acuity in that eye. Over time, that eye becomes amblyopic.

If the strabismus is intermittent or alternates between eyes, there are periods when the eyes align and binocular input can support normal development, reducing or preventing the typical unilateral amblyopia pattern. While other factors like refractive error can cause amblyopia, the classic amblyogenic scenario described here is constant unilateral strabismus during the critical period of visual development.