There are many roles for eye drops, briefly divided into the following categories: first, anti-fatigue eye drops. Second, the treatment of dry eye eye drops. Third, anti-inflammatory eye drops, anti-inflammatory eye drops are divided into anti-bacterial, anti-viral, anti-fungal and hormonal anti-inflammatory drops, as well as non-steroidal anti-inflammatory drops. Fourth, in ophthalmology, a common treatment and examination-related is a dilated pupil drugs, ophthalmology there is another major category of eye drops, glaucoma-related drugs, which have various principles to lower eye pressure eye drops. The difference between eye drops and systemic medication is that the eye is a special organ and the effect of local medication is often greater than that of systemic medication, which not only has side effects but also has very little effect on the eye.