HP Compaq Presario,Presario 1515 Supplementary Manual page 21

If you wear bifocals or trifocals, it's especially important to properly adjust your monitor
height. Avoid tilting your head back to view the screen through the lower portion of your
glasses; this could lead to muscle fatigue in your neck and back. Instead, try lowering
your monitor. You may want to consider using monofocal glasses that are specially made
for computer use.
J
J
Take the time to eliminate glare and reflections. To control daylight, use blinds, shades,
or drapes, or try other glare-reducing measures. Use indirect or reduced lighting to avoid
bright spots on your display screen.
If glare is a problem, consider these actions:
Move your monitor to a place where glare and bright reflections are eliminated.
Turn off or reduce ceiling lights and use task lighting (one or more adjustable lamps)
to illuminate your work.
If you cannot control the ceiling lights, try positioning your monitor between rows of
lights instead of directly beneath a row of lights.
Attach a glare-reduction filter to your monitor.
If you wear bifocals or trifocals, don't position your monitor
so high that you have to tilt your head back to view the
screen.