Pupil not dilating, vision impairment

[bmayer]

I have an 18month brown leghorn hen that is having some eye issues. Her left eye pupil is not working and dilating and there seems to be vision impairment in that eye only. She won't let people on her left side and seems to be looking at her world from just the right eye. There may or may not be some very slight murkiness/cloudiness to the left eye. Other than her vision, she is acting 100% normal (eating, drinking, laying, interacting with other, etc).

Any ideas what causes this?

 

[Eggcessive]

Eye infection or cataracts can be common in chickens. Are both eyes the same color, and the same as they have been? Here are a couple of good articles about the common eye disorders:
http://edis.ifas.ufl.edu/ps031
http://joneshamiltonag.com/wp-content/uploads/PLT_Poultry-Eye-Disorders.pdf