Why Cats Get Black By Eye Gunk. It may be that your cat has feline herpes (viral rhinotracheitis, or fvr), or a fungal infection. That's why i worried it was blood.
First, there can be the presence of a watery discharge coming from your cat’s eyes. It's the proteins in cats eye fluid turns brownish when they dry out and comes in contact with air. It took a while but i worked out that he can’t eat wheat.