Whitetail Deer, Eye, Level pupil, head pointing down

[Terry V]

That's a perfect picture Rick. Thanks!

[Terry Vining]

a little eye rotation and a lot

[Terry V]

Sorry about your deer Rick. He takes great photos.

[Terry Vining]

Hey George, This guy needs a bigger eye.

[George Roof]

Gotta a spare set of bison eyes right here.  LOL

[Glen Conley]

Here's two photos for the people who don't know what they are looking at.

The first photo shows a skinned out deer head and the white scelera/sclera jumps right out at you.  Notice the EYE LIDS are absent.

I enlarged and lightened the exposure to show the structures of the eye.

In the second photo, the blue arrow points to the pigmented section of scelera/sclera.  Notice how wide it is.  Now that you are informed, go back through the previous photos and take a REAL look at the live deer eye photos and you will see that in those photos only the brown pigmented scelera/sclera is exposed.

Not all deer will have pigmented sceleras/scleras, nor will all have white sceleras/scleras, and some will have variations of the two extremes displayed.

[Clear Creek Taxidermy]

what causes EHD?

[George Roof]

Clear Creek, you need to index that in the white box above. Bill Yox gave me a great updated lesson in what causes it with a long discussion from others.  The short answer to your question, however, is midges.