<prompt> Grades of binocular vision-Grade 1: FusionGrade 2: FusionGrade 1: StereopsisGrade 2: Stereopsis  <response>: Woh described three grades of binocular single vision - Grade I - Simultaneous perception. It is the power to see two dissimilar objects simultaneously. Grade II - Fusion. It consists of the power to superimpose teo incomplete but similar images to form one complete image. Grade III - Stereopsis. It consists of the ability to perceive the third dimensiondepth perception. Ref; A.K.Khurana; 6 th Edition; Page no: 342 