What symptom indicates a child might have an eye problem after a blow to the head?

Double vision is a significant symptom that suggests a potential eye problem following a blow to the head. When a child experiences trauma to the head, it can affect various structures in the eye or the brain areas responsible for processing visual information. Double vision, or diplopia, can occur if the muscles controlling eye movement are affected or if there is damage to the nerves that help manage those muscles.

This symptom is particularly concerning, as it may indicate underlying issues such as concussion or other injuries that need prompt medical evaluation. Recognizing double vision as a symptom can be crucial in determining the necessity of further assessment and intervention to prevent long-term consequences related to vision or brain function.

The other options do not directly relate to typical symptoms following head trauma. Difficulty singing may suggest broader communication or processing issues rather than a specific eye problem. Increased alertness and heightened enthusiasm for activities might reflect a child's general emotional response to an injury and do not indicate any visual impairment or eye issue.