Hyperopia reserve is the built-in farsightedness babies are born with. As eyes grow, it decreases, ideally reaching zero by adolescence. If it runs out too fast, the child becomes nearsighted.
But too much can also be a problem. Significantly above-normal reserve means significant farsightedness β causing eye strain, squinting, and potentially amblyopia.
The sweet spot at age 4-5: about +2.00 to +2.50 diopters. +3.00 or more needs monitoring.
What matters: outdoor time (natural light protects against myopia), limited screen time, regular eye exams from age 3. The goal isn't maximum reserve β it's the right amount for your child's age.