An exemplary lens holder (30) includes a lens holding platform (35), a base (31), a resilient element (33), and three platform supporting members (32). The platform supporting members (32) connect the lens holding platform (35) with the base (31), and are aligned on different axes. The resilient element (33) is positioned between the lens holding platform (35) and the base (31), and configured for uniformly resisting the lens holding platform (35) away from the base (31). One of the three platform supporting members (32) is adjustable, thus adjusting a gradient of the lens holding platform (35) relative to the base (31).