It can have a significant impact on your visual comfort and efficiency. Lower lighting can be achieved by using fewer bulbs or fluorescent tubes. Or, by installing lower intensity tubes or using dimmer switches. The contrast between the characters on the screen and the screen background should be high. Use window shades or drapes to block out excessive sunlight.
Antiglare screens are also available.
To test for glare problems, place a small mirror on your VDT screen. You should not be able to see any light bulbs or window which should act as a source of glare. Move your VDT to eliminate the problem. Consider your workstation A visually oriented workstation is designed with your eyes and productivity in mind. The screen itself should be positioned 16 to 30 inches from your eyes with the top just below eye level.