Eyelid question

Hi vets - would love a second opinion on this. Our dog developed this seemingly overnight right after a healthy annual visit where she got shots. No discharge, pus, scaling, itching that we've noticed. Not affecting eyeball itself or vision. Not really bothering her. Our vet thought it might be contact dermatitis and said to just keep an eye on it. It hasn't changed in a week - same size and appearance and I've taken daily photos. Any ideas what this could be due to? No other medical conditions and no known allergies. Spayed female 1.5 yrs old. Thanks for any advice!!

Hello - there will be a huge list of differentials (possibilities) for this eye.  Sometimes inflammation goes down with minimal interference eg if due to an insect bite, nettle sting, trauma, allergy etc. but there may be a range of other differentials, from demodex mites to skin cancer to a local foreign body, to ringworm, so if no change then a follow-up consultation sounds to be a good idea, in case for example a biopsy is indicated.