Prolonged TV and computer use will not cause cataracts, glaucoma, floaters, macular degeneration or otherwise damage the eye. It can cause eye fatigue and strain, and in younger people can predispose to myopia or increase of myopia.
Many TVs and computer monitors have a way in their settings to adjust the color temperature of the display. To reduce the blue component of light select a color temperature of warm (less blue) or similar rather than cool (higher blue) - has the same effect as using blue blocker filtering glasses.
I have a question: does watching TV up close with minus glasses make you even more myopic? Or the lens doesnt affect near objects?