Your computer monitor should be straight infront of more than 25 inches from your eyes.
Use a screen mounted document holder,positioned between keyboard Á monitor screen almost at the same distance Á height as that of the monitor.
The ideal viewing area of the monitor is 6 inches,below the horizontal eye level.
Use suspended lights from ceilling Á windows with shades,blinds or curtains,avoid light hitting directly on eyes.
Preferably work with font of darker shades on light background Á viceversa
Use chairs with armerests which are able to provide,support while typing,position of head slightly titled downwards Á height of the chair adjusted appropriately so that the feet rest flat on the floor
Attach a anti-glare screen in front of the monitor,which will decrease the amount of light reflacted from the screen.
Avoid sitting at a location with direct blow of air on eyes from a blower or an A.C. or a long peroid in a room with low humidity
Take short breaks for your eyes every 20 minuites between your work for 20 seconds then look at objects that are atleast 20 feet away.
Close your eyes and slowly roll your eyeballs clockwise Á anticlockwise. Repeat it for 3 times.