Cockatiel Eye Question

Question
I have a three year old cockatiel female. I noticed recently that she has a problem with the inner lining of her eye. It seems to come up above the bottom lid and is slow to retract at times. I have four cockatiels altogether so it is possible it was injured. It doesn't seem to bother her and she is able to see. Any ideas?
I appreciate your advice and await your answer.
                      Sincerely,
                   Melinda Ferguson

Answer
Hi, Melinda.  Thanks for posting!

I think what you are seeing is a protective mechanism for the eye.  Here are a couple of extracts from websites on the internet relating to avian eyes:  

The Eyelids - birds have 3 eyelids; one upper and one lower eyelid, of which the lower is more moveable, and a nictitating membrane. This nictitating membrane is between the other two eyelids and the cornea and has its own lubricating duct equivalent to our tear duct. It is used in cleaning and protecting the eye.

Birds have three eyelids, and so do dogs and cats. The upper and lower eyelids have small bristle feathers that resemble eyelashes. Most birds only close their eyelids during sleep, and use the third eyelid alone for blinking. The third eyelid, the nictitating membrane, lies beneath the eyelids on the side of eye closest to the nostril. It darts across the eye about 30-35 times per minute in the domestic fowl, and also moves across the eye if an object approaches the eye suddenly or if something touches the head. The third eyelid becomes scooplike and sweeps excess fluid in to the corner of the eye where it drains. In most birds, the nictitating membrane is transparent, so vision is not impaired when the eyelid blinks, which is important since so many birds are prey animals. It helps to be able to see when blinking! It is suspected that some birds may fly with the third eyelid covering the cornea of the eye, which prevents it from drying out during flight, acting like birdy goggles.

If you think something is wrong with your tiel's eye, I recommend you consult an avian veterinarian.  It's possible for an eye injury to occur when several birds are housed together, but most of these type of injuries would be more like a peck in the eye resulting in loss of eye fluid or a cut or scratch from a beak or toenail.  Your tiel could have actually injured herself with her toenail when she tried to scratch herself on the face.  However, there may not be a problem at all.

Sorry I can't help much here, but I don't have much experience with eye membrane problems.  Most of my experience is with eye infections, pecks to the eyeball itself, eye cuts/scratches, etc.

Chrys