Clean a scratched lens

[gbc364]

How to clean the lens, projection is blurred.

 

[gbc364]

How do clean the lens on flat screen.

 

[Sedivy]

If it's a scratch all the way down to the glass, then you have to change the glass (unless you've got someone who can polish lenses but that takes specialized equipment and is rare). If it's just minor scratches in the coating, then those you can generally smooth out when cleaning the lens but take care what you clean it with because you can make it worse if you use the wrong stuff. Cause of work, I usually have access to special lens paper and cleaning products, though distilled water or very diluted alcohol (20:1, use pure stuff from the pharmacies, nothing from grocery stores) and a microfiber cloth will do. Some people use wax or vaselline on scratches on glasses and such. I'm not allowed to use any of that stuff so can't recommend it.
Just saw your second post. I am talking about glass lens of the projector. Don't know about flat screen, the above does not necessarily apply for that.