A person that deals with optometry are referred to as an optometrist, while a person who deals with ophthalmology is called ophthalmologist. They both deal with eye treatment, but the optometrists do not have a medical degree certificate, meanwhile, the ophthalmologists do. The optometrists can obtain an optometry degree, though, but there is an extent to which that can go. They can only deal with some physical parts of the treatment and prescribe drugs or give control measures, but they cannot perform surgical operations on the eyes.
On the other hand, ophthalmologists are like medical doctors; they possess furthered or higher education than the optometrists. They can diagnose the eyes, manage, and even perform surgical operations on them. Their work is broader, and they can deal with relatively every infection that has to do with the eyes. Hence, optometry deals with a surface treatment of the eyes, while ophthalmology deals with a deeper treatment of the eyes.