Patent attributes
Disclosed herein is an optical device for restoring eyesight, which includes a first tube configured such that a first convex lens having a first focal length is installed to an inner peripheral surface of a fore-end thereof, a second tube inserted into the first tube so as to move forward and backward within the first tube while a first concave lens having a second focal length and a second concave lens having a third focal length are installed to an inner peripheral surface of a fore-end thereof, a third tube configured such that a third concave lens having a fourth focal length and a fourth concave lens having a fifth focal length are installed to an inner peripheral surface of a fore-end thereof, a fixing unit for fixing the second tube to the third tube, and a fourth tube fixed to the fixing unit to cover the second tube.
