Contained in a Field & Stream blog post, most relate to American waters but I was struck by the following:
“16. Make Glow-in-the-Dark Flies
Many of the best mayfly hatches happen after dusk, when it is difficult for mere mortals to actually see trout eating their flies. To avoid missed strikes, organize a dedicated late-night fly box. Set aside some of your key patterns, and use a fine-point paintbrush to dab the tips of fly wings (or the posts of parachute patterns) with glow-in-the-dark paint. Be conservative, so as not to add extra weight to the flies, and only treat the top sections (where you’ll see it, but the trout won’t).
Paint your flies at least 24 hours before fishing them, and before you hit the river, spend a good five minutes or so shining a bright flashlight beam into the box, so the paint absorbs the energy. If the glow-in-the-dark spot on the water disappears when you hear a slurp, set the hook.”