Abstract: Various aspects of the subject technology relate to systems, methods, and machine-readable media for virtual try-on of items such as spectacles. A virtual try-on interface may be implemented at a server or at a user device, and may use collision detection between three-dimensional models of the spectacles and of a user's face and head to determine the correct size and position of the spectacles for virtual try-on. With the determined size and position, a virtual representation of the spectacles is superimposed on an image of the user.

Abstract: A lensmeter system may include a mobile device having a camera. The camera may capture a first image of a pattern through a lens that is separate from the camera, while the lens is in contact with a pattern. The mobile device may determine the size of the lens based on the first image and known features of the pattern. The camera may capture a second image of the pattern, while the lens is at an intermediate location between the camera and the pattern. The second image may be transformed to an ideal coordinate system, and processed determine a distortion of the pattern attributable to the lens. The mobile device may measure characteristics of the lens based on the distortion. Characteristics of the lens may include a spherical power, a cylinder power, and/or an astigmatism angle.