Myopia is near-sightedness, corrected by a concave lens, while hypermetropia is far-sightedness, corrected by a convex one; power in dioptres is the reciprocal of focal length. I know this from my 8th-grade science textbook, but the real lesson came from my daughter's teacher saying she was squinting at the board. We got her spectacles just last month—a simple concave lens, but the delay makes me regret every time I postponed the check-up, thinking it was just a habit. Now I see that knowledge in a book is one thing, but acting on it for your child is everything else.
#exams#study
Jump in to reply — no account needed.