Also for light sensitivity: Download and install "f.lux" software here:

http://stereopsis.com/flux/

It is free, quick, and easy. It filters the blue light out of your screen at night, and you can click on the icon it creates in the lower right-hand portion of the screen to set it to always filter out the blue light (it's set to do so only between sunset and sunrise). I find the softer, more yellow light to be much easier on my eyes than the normal blue light of most computer screens.