This device has the following characteristics - A Joy Stick that does not require much effort and good alteration for all the positions of a body with a single limb. - It is not heavy and has a firm body. - It is the device that has the capacity to solve the issues and gives the accurate picture. - Has a lot of parts that can be used on different situations. - Made up of Haag Streit Model. - Provides more support for chin in order to conduct eye test easily.