Your lens develops a dirty yellow colour cast, shifts focal length, loses contrast and develops the most awful flair. A photographers nightmare - no reality for many of us as we get older, the lens in queston being the one in our eyes. It has happened to me very rapidly over the last year affecting one eye very noticeably. Ten days ago a new lens was implanted in the affected eye- plastic not L glass! What a difference. Whites look almost blue, greens are green and there is not as much dirty haze in the sky as I thought.
Cataract is often written about as occasionally affecting artists - Monet is the most quoted example. Look at any of the opthalmology web sites and you will see how common it is. Two of the others having surgery on the same day as I did looked to be in their forties.
I guess my reason for posting this is as a reminder that colour management starts and ends with the eyes and they can go off very badly. (I am now aware that what I had thought to be my good eye has a yellow cast)