Glasses in general relax your eyes

If you aren't used to wearing anything, your eyes will dilate and they can feel sore and dry without UV interference.

My problem was the lack of frames, these were rimless and probably more fragile than some thick plastic ones like the ones we had as children.

I suspect now things are made much more cheaply and thus cheaper glasses are less well-made than their equivalent when Hardup was a lad. Cheap consumer durables now are worth every penny - getting a reasonable pair shouldn't cost the earth like designer brands do, but a mid-range pair probably have more protection and are more robust than ones you just pick up from a seaside kiosk.