Ultraviolet light from sunlight can cause certain plastics to yellow or fade their colors, and I've seen claims that fluorescent lights can do the same to a lesser degree.  I have some vintage computer equipment directly underneath a 4' lamp, and I'd hate to degrade the plastic.  Is this a major concern, and can it be mitigated with the use of a polycarbonate tube protector?  Is a special (and pricier) "UV Blocking" guard worth the extra, or will a standard one do just fine?  I know even the regular ones at least block UVA from blacklights.