Polycarbonate cracking in zyl frames (follow-up)

[snowmonster]

There was a discussion going on about 1.5 months ago about polycarb lenses cracking in zyl frames. Some people had theorized that certain frames would interact/bleed chemicals into the lens and cause them to crack.

We had noticed this quite a bit lately, and I think I've figured out the solution. We had been using isopropyl alcohol to clean lenses after they had been inserted to remove any permanent markings, etc. I believe the alcohol got inbetween the lenses and the frames and caused some sort of problem where the edge of the lens would crack 360 degrees.

Since switching from alcohol to regular lens cleaner, this problem has pretty much gone away. We still use the alcohol to remove any markings on the lens surface, but we're not actually spraying the whole lens/frame combo with alcohol. We're just wiping the surface where the dots/markings are.

Just a little follow-up...

-Steve

[Chris Ryser]

We still use the alcohol to remove any markings on the lens surface, but we're not actually spraying the whole lens/frame combo with alcohol. We're just wiping the surface where the dots/markings are.

Steve..........You are OK with alcohol on the surface as it is protected by the hard coat.

However the standard regular lens cleaner used in the optical trade by just about everybody is nothing else Than 70% water and 30% ISP (Isoprproyl alcohol) This will not work as fast on the poly as pure undiluted one but might still lead to cracking at a later date. (chemicals reactions on poly are aften a delayed result)

On poly and AR coated lenses one should really only use surfactant based lens cleaners that bare more expensive but will prevent problems with Poly and AR coatings.