I have several Hyperlite UFO LED high bay lights in my shop and they have quite a bit of glare. Hyperlite wanted TOO much money for their diffusers (almost the same price as the light itself). I finally got around to making this diffuser with clear PETG. The length of the diffuser makes it so that the light source can't be seen directly from as close as 10ft, so unless I'm close to the light looking up this works very well. I used #4 x 1/2 sheet metal screws to thread into the already existing holes. The housing temperature was only around 43*C after several hours of being on so PETG should work great.

Print this with the mounting flange on the plate.
Using the random z-axis got rid of some anomalies.