Abstract: A head-mounted device may include optical assemblies for presenting images to a user. The optical assemblies may each have a display for generating an image and a lens that presents the image to a corresponding eye box for viewing by a user. The optical assemblies may have lens barrels. Each lens barrel may have a first end to which a display is mounted and may have an opposing second end. A mount may be used to attach the lens to the second end of the lens barrel. The mount may have at least one flexure. The flexure may have a U-shaped cross-sectional shape. The mount may have a ring-shaped flexure that extends around a peripheral edge of the lens, may have flexure segments, or may have a set of three discrete flexures located at different positions along the edge of the lens.

Abstract: Wavefront sensors are provided herein. An aperture mask is configured to receive incident light the wavefront of which is to be measured and comprising irregularly spaced apertures that respectively transmit sub-beams of the incident light. A diffuser is configured to receive the sub-beams transmitted by irregularly spaced apertures of the aperture mask. A camera, having a focal plane in which the diffuser substantially is located, is configured to obtain a digital image of the diffuser and thus to obtain a digital image of the incident light the sub-beams of which the aperture mask transmits onto the diffuser. A controller is configured to electronically receive the digital image of the diffuser and to measure the wavefront of the incident light based on the digital image. Methods also are provided.