Ok, well the greenish yellow discharge can be a number of things. Of course the first thing that comes to mind is an infection when you see discharge like that, but there are some other things to be aware of in dogs. The main concern when I see a dog with discharge from the eyes is whether or not there is ulceration on the corneas (meaning the top layer of the clear, outer-most part of the eye has been eroded). If there is an ulcer or a scratch present on the eye, it needs to be monitored closely to make sure it heals. If not, then it can continue to erode and potentially even perforate the eye. Ulcers are not always visible with the naked eye, and often need a stain to make them show up.
There is also a chance that your dog has a foreign body under the eyelid causing irritation and possibly a secondary infection.
There is another disease called KCS or "dry eye", which is caused by an immune system malfunction which decreases tear production. This causes the eyes to become dry and painful, and often will cause a yellowish mucoid discharge from the eyes. This disease is ruled out by performing a Schrimer Tear Test.
If both eyes are affected, then allergic conjunctivitis is also a possibility. If it is allergies, unfortunately the antibiotic drops you have are not likely going to work. You will need to use a steroid, but again, you want your veterinarian to make sure that there is no ulcer present on the cornea before using a steroid, as they will make ulcers much worse. Keep in mind that eye diseases can progress rapidly (but they also heal rapidly when treated appropriately).
There are some other diseases such as episcleritis (redness and inflammation of the white part of the eye) and even some types of cancer that can affect the eye and cause a discharge, so ruling these out with a vet visit is a good idea.
As far as using human drops in a dog, it definitely is possible, however I wouldn't use them without having a veterinarian examine the dog first. In terms of saving some cost, you could bring the meds you have with you to the vet and ask if there is one of them that would be suitable so that you don't have to purchase more.
I hope this helps.
If you have found this information helpful, please click ACCEPT so that I may be compensated for my time and knowledge.
The information contained in this post is not meant as a diagnosis and can not take the place of an examination by a veterinarian.