When entering a texture pack that modifies some mobs slightly or modifies them in various aspects, the textures do not load correctly and various parts of the texture are buggy and the one that is most buggy is the one of the eyes.
At capture time try to use the "Fresh Animations" texture pack.
MC-254810
Texture packs don't load properly and eye texture bugs on all mobs.
Resolved
Invalid
0
This isn't a bug with Minecraft. This is because you didn't install OptiFine, which is required for the texture pack. Always read the descriptions of resource packs to check if they need it. You can install OptiFine at: https://optifine.net/downloads
If you do have OptiFine installed, make sure that "random entities", and "custom entity models" are enabled. If it keeps happening, try removing any other resource packs.