ultraviolet

So,,I am trying to wire up two 5mm UV LEDS to backlight my vasaline marble monster eyes. I have done LED's before with no issue but for some reason these little devils appear more tempermental. I think the heat is getting to them during soldering since they work just fine temporarily wired with...

I purchased hand full UV Leds, 5mm ...I'm wanting to blur the LEDs lens so the light give a more wash or flood effect vs a spot or narrow beam. I know this is primary due to the display angle, but, what about putting something like plastic wrap for covering food, or even vasoline over the lens...