I have a puppy who was born Oct 7. A few days ago he opened one eye, but the other is still firmly shut. Is this normal or at what point does he need to see a vet just for this?

hes 1/2 Maltese (dad is full Maltese), the mom looks border collie but I know her mamma looked like a Chihuahua But was a mutt. They had no clue what the father was so it was a shock to see her grow up looking like a border collie. So who knows what the other half consists of.

he is nursing well but doesn't always get his fill so he does get a little goats milk in a dr browns bottle.

I'm including both photo and a short video uploaded to YouTube.

Any ideas or suggestions?
The inner most corner looks like it's open and you see a bit of an eye but the majority looks to be fused for lack of a better term.

Thanks for the help in advance.