A school vision check asks a child to read a chart at six metres. It is a good test of one thing and a poor test of almost everything else.
The critical limitation is that it is usually conducted with both eyes open. A child whose right eye sees clearly and whose left eye does not will read the chart perfectly using the right eye alone, entirely unconsciously, and be recorded as normal. Nothing in the procedure is designed to detect the imbalance.
What that child then carries into a homework-heavy CBSE timetable is asymmetric visual function: adequate distance vision, poor or absent depth perception, and near work that costs more effort than it should. Reading stamina suffers long before anyone thinks to question the eye report.
One Question to Ask the School
Ask whether the screening measured each eye separately with the other covered. If the answer is no, or nobody knows, the report cannot exclude amblyopia — and a twenty-minute optometric examination can.