Viewer having variable focus lens and video display system

摘要

A viewer includes a varifocal lens and a lens controller that adjusts a focal length of the varifocal lens, and can adjust a focal point in accordance with eye movement of the user. When a 3D image viewing detector detects 3D image viewing by the user, a focal length fixing section instructs a lens controller to fix a focal length of the varifocal lens irrespective of eye movement of the user.