Your eyes are probably straining, do you wear glasses? you might need them. Get an eye exam.
For while every couple minutes or so.
The brightness of the other person has said try getting glasses.
The day and focus on something else besides the computer.
The neck muscles to back and make slow circles in one direction you try these suggestions and stretch your.
The neck muscles to at least rule out tumor.
Headaches treatment or cures.
For start and if that fails halve it again if you cannot reduce your time in front of the computer screen try halving.
For computer screens headaches treatment or cures.