How tight do fly masks have to be?

A situation that you won't quickly forget once you've experienced it:
A horse gets completely upset because a fly got into his eye mask and can't get out. It's hard to catch and is thrashing its head around wildly.

The popular opinions on this:

Viewpoint 1:
Eye masks for horses must fit very tightly around the edges so that no flies can get under the mask. Ideally with an elastic band that adapts flexibly to the horse's head.

Viewpoint 2:
It is better if the masks on horses fit loosely so that flies that get underneath them can escape again. Even tightly fitting fly hoods can slip and if an insect gets into it, it will be very difficult to get out again. Quite often with the result described above.

We at innoHorse represent point of view 2.
Although the innoHorse light protection masks fit rather loosely on most horses, the horses do not lose them if the Velcro fasteners are adjusted correctly. You hardly ever see insects under the masks - but if they do happen, they find the exit again.