Questions about new daschund puppies

We have four daschund puppies (born Dec.22).
I've just noticed today that one has an infected eye - proabably 'helped' by one of our kids unfortunately....
What can I do to help this puppy's eye?
When can we expect their eyes to open as they are now 15 days old?
And is this likely to affect the pup's vision when it gets over this?

 

Hi at 15days old there eyes should be open but some take longer than others.
As for the eye infection, cotton balls dipped in warm salt water usually does the trick, but with a puppy so young i would take to the vets to have him treated..
It is unlikely it will effect his vision as most pups get what looks like an eye infection when there eyes open, But without seeing a vet you won't know how bad it is..

Mike