Tadpoles' eyes have a kind of lens called "magnifying glass", which enables tadpoles to broaden their horizons and better observe the surrounding environment. In addition, the tadpole's eyes also control the amount of light entering the eyes by adjusting the pupil size, thus adapting to different lighting conditions.
It is also worth noting that tadpoles usually live in shallow water, which means that their environment is bright, so that their small eyes can also see things around them.
In short, although tadpoles have small eyes, they can better perceive the surrounding environment through mechanisms such as lens and pupil, which is an important guarantee for their normal life and movement.