A person only reads character when 25cm from her eyes. Calculate the dioptric power of a lens she need so that the characters are clear at 1m distance
To calculate the dioptric power of the lens needed, we can use the formula:
Dioptric Power = 1 / Focal Length
Given that a person reads characters at 25 cm (0.25 m) from her eyes, we can assume that the focal length of her eyes is 0.25 m.
To calculate the dioptric power for clear vision at a 1 m distance, we can use the formula:
Dioptric Power = 1 / 1 - 0.25
Dioptric Power = 1 / 0.75
Dioptric Power ≈ 1.33 diopters
Therefore, she would need a lens with a dioptric power of approximately 1.33 diopters to have clear vision at a 1 m distance.