Gridiness and headache. On computer.

I have 2 episodes of vertigo in last 6 months. .I consulted with ENT lot of test conducted like VNG, audiometry every test was ok...ENT doctor advise that it may not be vertigo. ..advise to consult to neurologist. .MRI conducted MRI was ok...again I consulted with ENT...and as advised by doctor I am taking stuzeran 25 and renerve plus from last 4 months there is minor improvements in Diziness and motion sickness. ..however from few days I am feeling headache after sitting 2-3 hours on computer...I visited with opthalogist also my eyes are ok...Please advise what can be the reason of such headache...I have consulted with lot of doctors in last 6 months. .but in last 6 month noboday has diagnosed the root cause of my problem