Question

If we bring an object closer than 25 cm from the eyes, why can we not see it clearly even though it subtends a bigger angle at the eye?

Answer 1

Although the eye lens's focal length can be changed, it cannot be lowered below a certain limit. Therefore, the minimum distance of distinct vision is the distance from the eye at which an object is clearly visible without causing eye strain if it is very close to the eye. It is 25 cm for the average human eye.