Question

What type of lens does drop of air bubbles behave

Answer 1

This behaves in a way that is equivalent to two concave interfaces if the light were entering from a medium with a lower refractive index into one with a higher refractive index. Therefore an air bubble in water acts in the same manner as a concave lens made of glass does in air

Answer 2

Here is your answer.

CONCAVE LENS (DIVERGING LENS)

HOPE IT HELPS YOU.