Keep lowering a part of the eye... (6)
I believe the answer is:
retina
This might be a double definition.
'keep lowering' is the first definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'a part of the eye' is the second definition.
('retina' is part of 'eye')
Can you help me to learn more?
(Other definitions for retina that I've seen before include "Light-sensitive eye lining" , "Eye's membrane" , "Retain with part of eye" , "Membrane that can become detached" , "Bad tear in part of the eye" .)