A detailed assessment including the assessment procedure and the result in visual space of a projection lens design for head-mounted projective displays is presented. The influences of the focal length and the pupil size of the eye on the modulated transfer function (MTF) are sufficiently considered. The formulae to compute the loss in resolution due to accommodation shifts and astigmatism are given. The results show that for a 3 mm pupil size, the MTF is 0.55 at 0.5 cycles/(′), matching the visual acuity of the human visual system (1′). When the eyes gaze at the center of the projected image, the accommodation shifts of points in the full field of view are less than 0.35D. And the loss in resolution due to accommodation shifts is less than 3.5′. The maximum loss in resolution due to astigmatism is only 1.1′. The maximum value of the lateral color and secondary color are only 0.57′ and 0.17′, less than the visual acuity of the human visual system. The results demonstrate that the lens can fulfill the usability in head-mounted projective displays. That technique can be applied to all the HMDs.