Source :- ulisboa.pt
It is true that all dogs are born with the third eyelid which is quite common and natural but when this eyelid are visible to human eyes than there is definitely something you should be worried about. The third eyelid is often termed as haw or nictitating membrane and the color of this part varies in different dogs. Some dogs may have a clear transparent third eyelid while some have cloudy or translucent third eyelid. Sometimes it might make your dog look scary because while sleeping dogs often get their outer lids opened and they look as if they have all white eyes as their third eyelid still remains closed.
Source :- wagwalkingweb.com
If you thing that the eye lids are given to you just to apply your eye shadows and all the eye makeup than you are far from the real purpose of the eyelids which is to protect the eye from any kind of strange thing and it also helps in relaxing your eyes by covering them with the muscle mass. The third eyelid of the dog opens as well as closes from the inner corner of their eyes and each time their blink their third eyelid also goes through their whole eye and then opens up. Apart from just protecting the eyes it also helps in washing the eyes so in case the dirt has already entered in your dog’s eyes then also this third eyelid would help them get rid of the dirt in their eyes by washing it out. The third eyelid produces almost one third percentage of a dog’s tear which means that this third eyelid keeps their eyes hydrated for a long period of time. The antibodies produced by them also helps dog fight with any infection that takes place in dog’s eyes. The main work of this third eyelid is to make sure that their eyes are moisturized as well as nourished and also saves the eyes from the harmful effects of rough winds.
These were few facts about the dog third eyelid that you should know and take better care of them as well in order to keep your dog’s eyes protected.