Dentistry and Ophthalmology, who is more valuable as an investment

Dentistry. That is what you call dentistry is more valuable as an investment. To make an analogy, people have two eyes, but the teeth to 28 to 32, from the point of view of this number and probability you know what I mean. But from the degree of attention now, people pay more attention to the eyes, but with the improvement of people's living standards, the degree of attention to oral health will continue to be in the constant, climbing.