Portable corneal topographers and portable corneal topographer modules are disclosed. In one embodiment, a corneal topographer module comprises a housing having a first aperture and a second aperture formed therethrough; and a plurality of optical components disposed within the housing. The plurality of optical components are arranged to direct light generated by a light source through the first aperture to the cornea via a first optical channel when a cornea of a patient's eye is located adjacent to the first aperture; and direct reflected light from the cornea into the housing through the first aperture and to a light detector of a mobile device via a second optical channel when the corneal topographer module is mechanically coupled to the mobile device.