Abstract: This paper presents the algebraic method of isoplanat used in solution of the initialconstruction and its aberration design for ocular with long exit pupil distance of treblecomponents. The constructive mode is analysed. Algebraic equations of isoplanat aredeveloped, and the basic principle of aberration compensation by using the microcomputerprogramming is described. Finally, the constructive parameters and aberration consequ-ences of two numeral examples are given in this paper.