This document discusses signs that a preschooler may need glasses and the importance of identifying vision problems early. Some common vision conditions like nearsightedness and farsightedness are often congenital and caused by the shape of the eyeball. If a child has trouble seeing letters or becomes frustrated when learning to read, it could indicate an underlying vision problem requiring glasses. The first step for a parent concerned about their child's vision is to schedule an eye exam with their GP or optician.