Scott,
Dealing with "cleaner light," sometimes a simple term like this helps others understand the more technical term. How many understand the proper term "Color Renditioning Index" or the more cryptic "CRI." This relates to the visual problems that you mention and what I tend to call harsh light because it hurts my eyes after a time.
CRI - is an approximation based on the complete light spectrum of daylight and that is because we have no official definition of full spectrum light (the sun puts off allot of light that we can not see and even window treatments change the color of sunlight). There is also allot of flawed research into this area and the benefits of full spectrum light effects. Suffice it to say that a definition of CRI=100 was given to the standard incandescent bulb and is the maximum possible value.
Typically lighting designs should not be less than a CRI of 70, and I personally like to light offices at a minimum CRI of 80. Once above 90, the lumens per watt output of the available sources drops off and should be reserved for special cases such as museums or locations where color is extremely important.
Now looking at standard light sources and typical CRI's:
Metal halide: 65-70
High Pressure Sodium (HPS): 20-25
Ceramic Metal Halide:80-92
Highend HPS: 60-85
Fluorescent: 70-95 Some as bad as 50.
Compact Fluorescent(T5): Typically greater than 82, but I had the misfortune of finding some that I bet were about 50 for my house good thing they had an average life of maybe 300 hours (what a waste of money).
LED: Varies to much, look at each individually. New technologies have impooved so much that I am not qualified to guess what they are reaching now for some white sources.
Mercury Vapor: 40-50 (some as low as 20)
Thus, with metal halide fixtures at CRI=65-70 versus T5's at 82 plus the perception is allot more pleasing to the end user.
