"delian healer" is an epithet for

Apollo

Explanation:

The answer is: Apollo.

Explanation:

You're question has already been asked. "Delian" refers to the location of Apollo's birth, which is the island of Delos. Apollo was also known as a "Healer." He was known as "the Healer" and brought both healing and prevention of disease and sickness to the world.

the answer is subjective. i personally agree with the first answer for this question.

if one isn't strictly talking about objects then the correct answer would be 'my eyes' since according to this riddle i am asleep and in order to answer/open the door i need to open my eyes first of all.

however, if one is specifically looking for an object, then the first thing i would open would be the door

hope this !