Hi Sir or Madam,
Is the puppy able to close her eyes?
How old is the puppy now?
Was the litter born on time?
Your first thing to try would be to use a drop of sterile saline solution such as contact lens wearers use. A drop in the eyes may lubricate it enough that the eyes close. If this doesn't work or the eye doesn't stay closed, you will want your vet to check the pup over as soon as possible to check for eye abnormalities. He can stitch the eye closed for about 10 days to protect the tissue. If you use ointment, be sure to keep the tip of the applicator sterile to avoid eye infections from developing.
If the eye closes and stays shut, be sure and have the vet check for abnormalities at the first check up anyway and eye lid deformities might lead to this happening. . I hope this information is helpful to you.