My cocker gets that all the time - We use a special antibiotic ointment when it gets bad - your vet will know immediately if it needs treatment
Also - make sure the eye is hair free - the hair can irratate it - but your baby could have a little infection - I would get it looked at.
We also flush my cockers eyes with sterile water - the vet said to do this and it really helps - on cockers it's easy to see the red - on yorkies - I believe you'd have to lift up the lid to see if it's inflamed - if it is - I'd make an appointment - it's probably very minor but better safe than sorry...Good luck
