Problem with Dog's eyes - Third eyelid

My dog has had 4 incidents in the last 4 months.  Her "third eyelid" comes up to cover half of her eye, her eyes dart around and she looks like she's in distress.  It lasts only a couple of minutes. I have just started to look into this.  My wife has diagnosed this using the Google school of medicine and of course everything points to brain issues. Has anybody seen or heard of this and have any guidance?  Thanks

Hello!  You don't say what the rest of the dog is doing when this happens.  Fitting can sometimes look like this;  dogs can lose consciousness and therefore fall over and sometimes also convulse.   There are, however, so-called 'partial seizures' (old fashioned terminology now) which may affect just a nerve or group of nerves at some point along the length, not necessarily in the brain.  There can also be problems with the eye itself, such as pain, underlying lumps or spasms in the muscle.  Whether it's one of these presentations or something else, a veterinary appointment to try to name what is going on sounds like a good idea.  We would suggest calling your vet for triage - ie to establish how soon they would like to see you.  If it happens again before you see your vet, it would be a good idea to film an 'episode' on your phone to help them to understand what you are seeing, if you can do so safely (be aware that even the friendliest dogs coming round from fits or experiencing visual problems can be unexpectedly aggressive - due to confusion - so always be careful and keep any children well clear).  Are they reacting to their name?  What is the eye doing?  If they fall over, have they been to the toilet? This information, together with an eye and / or neurological exam can all be very helpful for your vet to start to reach a diagnosis.

If you don't mind taking a look, here is a link to a video of the last event: https://drive.google.com/file/d/1DcR5FyUAWxIS02DuU4523BqwfykDogfB/view?usp=sharing

Any luck?