The most common causes are digoxin's inhibitory action on the sodium pump, and the development of cataracts which can cause a yellow filtering effect.
It has been suggested that Van Gogh contracted xanthopsia as a result of digoxin consumption.
Digoxin is a medication derived from digitalis and used to treat various heart conditions.
This theory claims xanthopsia as the cause of the yellow tinting exhibited by many of his works.
[1] Xanthopsia is also a rare side-effect of jaundice, in which bilirubin may be deposited into the eye in sufficient quantity to produce a yellow tint to the vision.