Bryster:

Ah-hah ! ! now all the pieces fit into place - the house plants reacting to the light from the monitor causes you to turn down your monitor which causes you to suffer the effects of insufficient lighting which causes you to adjust your monitor which causes the houseplants to react to the light . . .  

I still think the lighting's O.K.  - on my 19" Trinitron (DELL) it looks ok anyway. 

Ah a stigmatism ! I've got one too; relatively minor, but it seems to varie just enough that I always have to doublecheck things like straight lines. For example: when roofing, I always have to snap a line to keep the shingles straight.