I would definitely stop feeding layer to a drake. You can get an all flock and put oyster shell on the side for the girls. Not saying too much calcium is your problem but it's not great for drakes.
Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
I apologize, I did not see he was a male. Since males don't need calcium, you should really switch to a feed like (Purina Flock Raiser, or All Flock Feed) that contains a decent amount of calcium, but not enough for it to pose a problem with males.
What has your vet done as far as a treatment to the eye?
What kind of diagnostic tests has your vet done so far?