Insect eye lens

Students look through the 'insect eye' (also called 'fly eye'), and draw their own art to look at with it.
The insect eye partly models how an insect eye works, but is not completely accurate.

Bees and other insects, as well as crustaceans, have compound eyes: https://en.wikipedia.org/wiki/Compound_eye

The insect eye lens roughly models what information is collected by a compound eye, but not what the animal actually sees.
Each of the tiny lenses in a compound eye collect light from part of the scene in front of the animal. These images are combined in the animal's brain to make one image.
The images collected by the lenses in compound eye are actually very low resolution (each one just colour shade with no details), unlike the insect eye lens (which is high resolution). Compound eyes collect information that would look like a computer image made up of very few pixels.
See this link: https://askabiologist.asu.edu/content/bugvision-hollywood-misconception.
When students make their own art work, and look at it close-up, the fly eye does at least show that each image is a part of the whole picture (a better job than the "Hollywood" version in the link), but is still too high resolution. Students that use the insect eye to look around them at further-away objects will have an even less accurate model (so I ask them to look close-up at a drawing).

Although compound eyes have very low resolution, they have a very large view angle, as well as the ability to detect very fast movement.
That is why it is almost impossible to catch a fly without a fly swatter or wide cloth.