It’s disturbing all right, but not because of the eyes, IMO.
I’m not sure what you mean; but the people back then thought very differently than we do today.
Pictorial Symbol was very important - most people couldn’t read. They ‘learned’ important concepts from paintings like this, and from all the other paintings, statuary - even the architecture itself - of the churches.
I think the original Lamb, as re-discovered in this painting, is very beautiful.