I posted this question over on TZ-UK a while back, but since my banning, I can't comment anymore..

Anyway, I've experienced misting on the underside of the glass on 3 Heuers I've owned.. the misting/clouding pattern on the underside of the glass mimics exactly the lume plots underneath. You might think that these are very old Heuers, but they weren't.. the guilty being.. a 75 Silverstone, an 80's 11063 and my 79/80's Monnin. So it can't be due to 50's lume! The Monnin and the 11063 are 'repeat offenders'.. i.e. they have had the glass replaced or cleaned, but given time (6 - 12 months) it starts to come back.

The answers over on TZ-UK suggested it was radiation burn, and someone even said that they had it with a Silverstone too.
I took my 11063 apart the other day and cleaned the glass.. just with a cloth and breathing on the glass. The Monnin is THE worst offender.. the glass was crystal clear around 10-12 months ago, and look at it now... pics taken this evening...

I'm wondering if this has anything to do with paint degradation we see on some Heuer dials - especially the 'painless wonders'.
Anyone else experience it or have any insight?

Stewart
- Heuerville