A system for measuring the size of a capsular bag of an eye of a subject includes a size indicator and a sizing gauge. The size indicator is configured for insertion into a capsular bag and includes a peripheral portion and a pair of arms. The peripheral portion is configured to engage the capsular bag. Each of the arms has a proximal end and a distal end, the arms being joined to one another at the proximal ends. The peripheral portion is joined to the distal ends of the arms. The arms form an angle that depends on a size of the capsular bag into which the size indicator is placed.