Class Notes
Science
CBSE
Question: PHYSICS
Human Vision and How We See Colors
1. Myopia means trouble seeing distant things clearly. One reason it happens is when the
eye grows too long from front to back. Another cause can be an eyeball lens that bends
light too strongly. Light rays meet too soon, landing in front of the retina instead of on it.
This creates blurry vision far away. A concave lens helps by spreading out the rays before
they enter the eye. That shifts the focus point backward onto the retina. Diagrams show
how uncorrected myopia focuses early. The corrected version uses a diverging lens to fix
the path. Vision clears once light lands where it should. Eye shape matters more than
people often think.
2. A person who has trouble seeing far away can clearly make out things only up to 1.2
meters. To fix this issue, a corrective lens is needed that bends light before it reaches the
eye. Such a lens must spread rays outward so the image forms correctly on the retina.
This kind of adjustment requires a concave piece made specifically for the individual. The
strength depends on how much correction is necessary for clear distant sight. Calculating
