Q - Can glass completely prevent ultraviolet ray penetration?
Does UV penetration depend on the thickness of glass? As a lab worker I
need to check my DNA samples using an UV illuminator. Are my regular eye
glasses sufficient to protect my eyes?
A ~ Glass is not a perfect UV blocker, but it is pretty darn good. The little UV
lamp you use will not be enough to injure your eyes if you wear glasses.
And yes, as you expect, the thicker the glass, the more UV it will block.
Basically, if thickness x transmits 50% of the UV, thickness 2x will
transmit 25%, 3x will transmit 12.5%, and so on. If you have access to a
spectrometer, you can check the transmittance of your glasses
http://www.newton.dep.anl.gov/askasci/chem00/chem00539.htm