Binocularity in infants typically develops by which age range?

Binocularity in infants typically develops by which age range?

• A. 3 to 4 months
• B. 1 to 2 months
• C. 6 to 9 months
• D. 9 to 12 months

Answer: (A)

Binocularity is the eye coordination that lets both eyes work together and fuse two images into one, a key step toward depth perception. In infants, this coordinated fusion typically comes online around three to four months of age. By this time, most babies can fix and track with both eyes and maintain single, aligned vision when looking at near or far objects. That’s why the three-to-four-month range best fits the normal development window for binocularity. If this skill hasn’t emerged by about four months, it may indicate a vision problem such as strabismus and deserves evaluation. The earlier window (one to two months) is generally too soon for true binocular fusion, while later ranges (six to nine or nine to twelve months) imply that binocularity should already be present by that point.

Binocularity is the eye coordination that lets both eyes work together and fuse two images into one, a key step toward depth perception. In infants, this coordinated fusion typically comes online around three to four months of age. By this time, most babies can fix and track with both eyes and maintain single, aligned vision when looking at near or far objects. That’s why the three-to-four-month range best fits the normal development window for binocularity. If this skill hasn’t emerged by about four months, it may indicate a vision problem such as strabismus and deserves evaluation. The earlier window (one to two months) is generally too soon for true binocular fusion, while later ranges (six to nine or nine to twelve months) imply that binocularity should already be present by that point.