Irritation of the eyes that occurs after hours of staring into a LCD or CRT computer monitor, where the millions of phosphor dots start to "burn" your eyes. This happens especially after looking at plain text for hours, such as when writing code.
Using the green-over-black color scheme while coding reduces raster-burn, as does wearing lightly tinted sunglasses, especially if they are polarized.
guy 1- Damn, I got hella bad raster-burn from that 72 hour hacking marathon I pulled.
guy 2- I told you not to take all that vyvanse man!