I have the clear sleeves and the room they are in was set up for photography so its light safe. I wanted to see if they really worked so I put a screen 52 inches under the light with a dime taped to it. Waited a week and washed the screen out. It was exposed a perfect dime circle. So I did the same test but only 4 days long, same results. I would not say they block 100% of the uv light. I tried the same test with only the bug light and nothing exposed so I am sure the room is good. I now have a cover over my screen rack to be safe. I would love for someone else to run the test with the clear sleeves and see what they get. The amber sleeves seem to work much better with no exposure after 4 days
