Eyewear can include lenses having perimeters that are customized for an intended wearer. The perimeter of the lenses can be determined based on anatomical features of the wearer's face, the wearer's field of vision, or other parameters specific to that individual. Determination of the lens perimeters can involve developing a three-dimensional model of a wearer's face and/or head, demarcating a lens perimeter over an obtained image of a user's face, or delineating the boundary of a wearer's peripheral vision. A provisional lens perimeter obtained by any of these methods may be modified in curvature and/or size to arrive at a desired final lens perimeter. Customized lenses can be fabricated based on the determined lens perimeters. The customized lenses can be assembled into completed eyewear that is customized for a wearer, for example having shapes, sizes, and designs not otherwise possible.