Systems for determining an individuals current focal distance by measuring parameters associated with binocular vision focusing using one or two contact lenses are provided. In an aspect, a system includes a first contact lens and a second contact lens respectively configured to be worn over first and second eyes of an individual. The first contact lens and the second contact lens respectively include first and second circuits configured to respectively generate first data related to the first eye and second data related to the second eye for determining the current focal distance.
