As eyes are very sensitive to light this is brilliant. Even altering the contrast and brightness control on PC this still manages to achieve what the buttons failed at! I felt it also lessened eye strain, sometimes the "white" on PCs is very bright and ok for a quick glance, a filter is brillian for reducing the relectiveness of the white. Would recommend any PC user obtains one of these. Only problem found was the arms used to rest on frame need to be shorter and it would have been nice if design team took into account different heights. Need to lower head to see the close X! That would be my only gripe.