An apparatus for sizing an intraocular lens and/or an ocular region of the eye of a subject, such as the anterior chamber, contains a sizing device and a measurement device. In one embodiment, the sizing device comprises a first leg having a first contact portion for operably engaging the ocular portion and a second leg having a second contact portion for operably engaging the ocular portion. The sizing device has a test geometry when placed within the ocular portion. The measurement device is adapted for determining a dimension of the sizing device based at least in part on the test geometry. The sizing device may also have a reference geometry when the sizing device in a reference condition. In certain embodiments, the difference between the reference geometry and the test geometry may be used for sizing the intraocular lens and/or the ocular portion.