A couple of days ago, I got out some shoes I hadn't worn for a while - have had them some years, but no occasion to wear them in the last 18 months. Sadly, the moulded "rubber" - synthetic? - soles fell to pieces as I wore them. I asked about repairs but, as I thought, they can't be repaired. But I was told that, kept in the dark, shoes with these soles do this. It's happened to a couple of other pairs, but after about 15 years of heavy wear, and the uppers were going. Can anyone throw light on this?