Do I need diffuser for SAD light box?

Most of light boxes I've seen does not seem to have diffuser on them. I guess using UVless leds won't cause problem without diffuser, but doesn't looking at LEDs without diffuser still cause eye problems?
IF I do need one, what kind of diffusing method should I use? ALso, does diffusing decrease light intensity? I would like to create 10,000 lux.

 I'd think you need a diffuser, otherwise the LEDs would be obnoxious to look at.  I tried to find the lux output of LEDs, but couldn't get any information.  I have the feeling it would be difficult to generate that much output.  LEDs tend to be directional, you'd be better off with fluorescents.  At least, that is my opinion.  

I built a SAD box with 3 daylight fluorescent bulbs--it ended up costing about $200--ugh.  I put a white plastic diffuser over it.  The light is nice.

There is a good Instructable called "SAD Box inspired" that has a design with  CFL light bulbs.
Re-design7 years ago
You don't have to look directly at the led's.  Reflected light is just as good.  Some have even postulated that light hitting the skin works as well.