Dirt and Haze INSIDE front corrector lens

Hi. I have a Meade 10" Schmidt-Cassegrain telescope that is 15 years
old. I took it out for the first time in about 7 years and noticed
that there is a milky film on the inside of the front lens. I dont
remember seeing this years ago when i used the scope more often. At
first i thought it was condensation/dew and that it would go away as
soon as i brought the scope inside. But even after airing it out, the
hazy film is still there. Is this normal? Is it possible that this is
some sort of factory coating? It seems kind of irregular and dirty
looking, like the inside of a car windshield that has fogged up. If
this is dirt, is there any safe and economical way to clean it? My
email address is: . Thank you.