Alpha-Crystallin A Chain (CRYAA) belongs to the small heat shock protein (HSP20) family and can be induced by heat shock. The expression of CRYAA is preferentially restricted to the lens cell. CRYAA may contribute to the transparency and refractive index of the lens. CRYAA has chaperone-like activity, preventing aggregation of various proteins under a wide range of stress conditions. Two additional functions of CRYAA are an autokinase activity and participation in the intracellular architecture.