Missing Eye Textures

The Problem

For a long time now, I’ve been having a problem with many of my models having their eye textures missing.
The models themselves work well, function properly, but I do not know much about files. I have discerned
that many models might share the same eye textures, because so many of my models are missing theirs.

Here’s an example screenshot; pictured are Bloocobalt’s HD Citizens. Behind them are various other ragdolls,
because various other ragdolls are missing their eye textures.

http://cloud.steampowered.com/ugc/578979510329389843/154693796D445DAA04002E421D77EA37486082ED/

I stood them up back-to-back so I could include two screenshots, because there are two problems I have noticed.
However, Steam fudged its pants and didn’t upload all of the screenshots I took.
(I also know that the Black Mesa dude is missing his helmet textures but I’m gonna worry about that later)

The HL2 HD citizens are different in that just the white “sheen” of the eye is replaced with the pink squares; for other
models, the whole eye is pink and black.

I made a help request on the Steam Forums, but unfortunately my post was soon lost to the flood of threads on that site.

If anyone could assist me here, I would be very grateful.

i seem to get this too, but only the women’s eyes textures. They are black instead of checkered…

I hate to bump, but I have been dealing with this for a long time and need help. I am willing to provide the necessary information to help as much as I can, but I can not solve this on my own. Please, I need the help!