When the dds uses the blue light to "cure" my filling, why do some use a plastic protector and some don't?

they usually put a flat plastic orange thing on top on blue light gun, but some dont use it when they cure a filling, whats it for and why dont they use it?

When the dds uses the blue light to "cure" my filling, why do some use a plastic protector and some don't?
It is a good idea for every dentist to use the "protector", but some dentists just divert their eyes and don't look directly at the light. The blue light is ultraviolet light and can damage your eyes if you look right at it. I guess sometimes the orange protector just gets in the way and so the dentist would rather just put the light right where they need it, look away, and then push the button to turn on the light. It only takes a few seconds anyway.
Reply:THE ORANGE/BROWN PLASTIC THING YOUR ARE TALKING ABOUT IS USED FOR THE SAFETY OF THE ASSISTANT/HYGENIST/DR. THAT BLUE LIGHT IS VERY BRIGHT SO IT CAN DAMAGE THE USERS EYES IF LOOKED AT DIRECTLY BUT YOU KIND OF HAVE TO LOOK AT IT TO SEE WHERE IN THE MOUTH YOU ARE POINTING IT. SO THE ORANGE PLACTIC PIECE BLOCKS THE HARMFULNESS OF THE BLUE LIGHT FROM COMING BACK ONTO THE USER OF THE LIGHTS' EYES. IT IS A CHOICE TO USE IT AND YOU DONT HAVE TO.
Reply:The light is extremely intense and should not be looked at. Even the light that bounces off of the tooth should not be looked at. The "plastic protector" allows the dentist to see where he is aiming the light by sheilding most of the intense light from his eyes. Failure to use the "protector" is just stupid on the dentist's part. Look at the sun without good sunglasses on then look into a dark mouth. That is what it is like if a dentist does not use a "protector". Temporarily blind. Long-term visual impairment is predictable.