I visited today optical forums and I discovered that some opticians are not honest opticians at all. As a matter of fact, many opticians want to take as much money from you as it is possible. They do not care about ethics. Opticians do not want to inform you what you pupillary distance is and they do not want give you your PD data. They want to keep it a secret. They fear that Zenni Optical, which is their biggest competition, will allow you to buy your prescription eyeglasses for a lot less money. It is said to see that so many opticians would do anything to keep you away from Zenni. Some opticians discuss on forums ways to avoid giving patients their PD. This is an unethical approach in my opinion. I am glad that Zenni helps people with finding what their PD is. There is a special iPhone application that allows people to measure their Pd on their own. All you need to have in order to be able to measure your PD is an iPhone and access to the application. I believe that each person has a right to have access to the cheapest solutions when it comes to prescription eyeglasses.