When I saw Cailean MacLeod using somethng like this, I thought 'what a good idea'.
It keeps your glasses and/or sun glasses dry inside your day hatch, while preventing them from being crushed by the other stuff in there.
Lakeland Plastic no longer sells this shape containers, but I was delighted to see Morrisons supermarket had a 2 for 1 offer.
When I returned to our local branch yesterday they had sold out, so they are popular.
Worth keeping a look out though. [Edit: Although the comment from Marcus below suggests this design might not be so good.]