Gorgons in the modern day make sure to either blindfold or put eye protection on most or all of their snake heads. In past times, gorgons dwelled in caves, and now in modern times they often go blind from the sunlight.
i think that killing a dragon should have catastrophic nuclear-fallout level environmental consequences tbh. their blood should scorch and wither the earth with fire and poison, the toxic fumes released as they decay should choke the land and all nearby living creatures, and the entire landscape where they fell should be transformed into a blighted wasteland where bleached leviathan bones loom upwards out of the ground as a warning that can be seen from miles away, the boundary markers of an exclusion zone.
i also think that it would be wonderfully ironic if those who sought the fame and glory of the title of 'dragonslayer' only ended up with the bitter, enduring reminder of the devastation they're responsible for. this is not a place of honor. no highly esteemed deed is commemorated here.
Ok, vote:
Can't they be both? They're nuclear fallout to everything else, but a nutritious whalefall to Creatures of Darkness. Things swarm a dragon corpse that aren't meant for the mortal plane but at least they eventually clean it all up, maybe after a few centuries. Not quick enough for people to notice that it's a good thing.
The boiling isles
In my own podcast, killing a dragon basically made America as we know today (basically allowing manifest destiny to occur) and caused massive strife in the lives of those who killed it. If you're interested in this weird, magical, alternate view of America you can listen here.