Final answer:
A loss of the red light reflex in a child can indicate conditions such as cataract, retinoblastoma, retinal detachment, congenital cataracts, or vitreous hemorrhage. Immediate examination by an ophthalmologist or pediatric specialist is necessary to diagnose and treat the underlying cause.
Step-by-step explanation:
A loss of the red light reflex in a child can indicate several medical conditions. A common diagnosis associated with this symptom is cataract, which is the clouding of the eye's natural lens. Other possible causes include serious conditions such as retinoblastoma, which is a malignant tumor of the retina commonly affecting children, or a less severe condition such as a retinal detachment, congenital cataracts, or a vitreous hemorrhage. In any case, a loss of the red light reflex is a concerning sign that warrants further investigation by an ophthalmologist or pediatric specialist. Difficulty with the red reflex can also arise from issues with the ocular nerve or other parts of the visual pathway like a growth affecting the optic chiasm.
If a child presents with loss of the red light reflex, especially when combined with other symptoms such as sluggishness, light sensitivity, and vomiting as described for Hannah, medical attention should be sought immediately to properly diagnose and treat the cause.