The 99p shop has specs. in plastic tubes. The tube has a clip but it can be a bit poorly fastened and the specs and bottom part of the tube tend to drop down. Fortunately the pocket for those and the phobile has a separator so the tube stays upright without the clip.
Whatever happened to the marsupium (also known as bum-bag)? I have 4, from just big enough for a few things in hot weather (Hasn't been used for a couple of years!) to enough for drink, food, thin coat, hat, gloves etc.; also one with a sort of mesh mini-rucsack inside it. I just wouldn't keep the wallet in it unless it's the small one round the front.