blindingly

https://tts.langeek.co/read?text=YmxpbmRpbmdseQ&hash=c67aeb279ee7cac7b7b1c784519fcfd9f95951a3&lang=en&cache-only=0&driver=googletts

These adverbs describe the amount of light that is available in a specific context, such as "dazzlingly", "brightly", "dimly", etc.