Most of this is from Wikipeida:
The normal human "Critical Fusion Frequency" is around 16 Hertz. This could explain why monitors acting at specific frequencys (multiples of 16hertz?) bother people more. (if 85hz bothers someone then 101 may bother them as well)
I would assume this is simmilar to how a helicopters blades will appear to spin backwards when they are starting. Your eyes 'take a picture' each time the blades have almost made a full rotation. So all you see is that the blades have moved back just a little when really they have gone all the way around.
If Your eyes 'take a picutre' when the monitor has refreshed exactly 4 times (for a 60 hertz monitor) then you may see a solid image, however if you're eyes are little slower for faster then the image will begin to flicker in the same way that the blades of the helicopter spin backwards.
One of the reasons that lcd monitors don't do this as much is because they dont actually 'refresh' the same way as CRT's, only the parts of the image that have changed are physically changed on the screen. In contrast a CRT monitor constantly has a beam of electrons that is scanning across the screen at whatever the refresh rate is.
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Most of this is from Wikipeida: The normal human "Critical Fusion Frequency" is around 16 Hertz. This could explain why monitors acting at specific frequencys (multiples of 16hertz?) bother people more. (if 85hz bothers someone then 101 may bother them as well)
I would assume this is simmilar to how a helicopters blades will appear to spin backwards when they are starting. Your eyes 'take a picture' each time the blades have almost made a full rotation. So all you see is that the blades have moved back just a little when really they have gone all the way around.
If Your eyes 'take a picutre' when the monitor has refreshed exactly 4 times (for a 60 hertz monitor) then you may see a solid image, however if you're eyes are little slower for faster then the image will begin to flicker in the same way that the blades of the helicopter spin backwards.
One of the reasons that lcd monitors don't do this as much is because they dont actually 'refresh' the same way as CRT's, only the parts of the image that have changed are physically changed on the screen. In contrast a CRT monitor constantly has a beam of electrons that is scanning across the screen at whatever the refresh rate is.
Actualy they renamed Netscape to Mozilla, then hacked up the code and and called it Firefox.