WordNet sense 1 (amazingly impressive; suggestive of the flashing of lightning):

fulgurant, fulgurous, eye-popping

WordNet sense 2 (making a strong or vivid impression):

impressive

WordNet sense 3 (shining intensely):

blazing, blinding, glaring, fulgent, glary

WordNet sense 4 (emitting or reflecting light readily or in large amounts):

bright