This might be a resource pack error or resource pack file corruption.
Luckily, as you can tell, it doesn't affect the gameplay in any severe way, but it just might be a file corruption or error. This really wouldn't be classified as a bug as it isn't a distributed bug that happens often to players who do select actions and in return, Minecraft "bugs out".
In your case, I would try to fix this by:
Reloading the texture pack you were using. This can be conducted by selecting another texture pack you have and equipping that as your texture pack. Exit your world, then exit Minecraft. Following those steps, enter Minecraft back again (same version) and before you enter your world, revert back to your original texture pack and then enter the world. This may or may not work depending on the files (if the texture file is really messed up or - if it works - it was a simple error in the world).
If that doesn't work, you can check if the Minecraft files for Enderman Eye Textures are intact and normal (Enderman eyes have a different texture file than the body itself).
You can also completely rid of Minecraft and all files associated with it and redownload a fresh copy of Minecraft.
You can instead use a different texture pack or an alternative texture download (if it is of the same texture pack you were using, the default pack, it can be found online).
Or lastly, you can just ignore the white eyes of the Enderman and just called them Enderbrines from now on.
Rollback Post to RevisionRollBack
"Actions should not be followed by regret. Regret should not be followed by remorse. Why do it, when you'll only feel bad in the end?" - SilentHunterX