Serum eye drops are using your own blood serum, which is similar to tears to support tears. You have to find a place that will do them (some Lion's Club eye centers) and have a prescription from your doctor. They take your blood, spin out the serum and give you small vials for your eyes. You have to keep them all frozen but one that you use for a limited period and then throw away. It seems like a complex system, but they really do help. Unfortunately the FDA hasn't gotten around to approving them, but most eye doctors support their use. If you have severe dry eyes, they help a lot. There is a company called Vital Tears that does them, although they are also researching also, so just be aware of that and ask to "opt out" if you don't want to be in the research. This company sees the commercial possibilities because serum eye drops are very popular. They don't produce tears, but are similar to what you tears should be (if your eyes don't make them) if you have SS or other issues.