if we heat glass cooktop can it wear off in 2 years

Are there any small cracks or broken seals in the stovetop? It sounds like they may be water stains from condensation.

If you can give the brand and model number, a Google search will determine if this is a common problem with it and if there is a solution.

There is a stove-top cleaner you should use regularly on the top surface. Do you use it regularly?

I think there must be some crack on the surface......that's why the white spots have been created.