Mammalian crystallins which are water soluble structural proteins located in the vertebrate eye are classified in three forms， labeled alpha， beta and gamma. Crystallins， the primary components of the lens， raise the refractive index of the eye all through the accommodation by creating high-molecular weight aggregates that maintain transparency. CRYGS is a monomer that does not aggregate. CRYGS encodes the most substantial gamma-crystallin in adult eye lens tissue. Gamma-crystallins has a part in cataract formation due to aging or mutations in specific genes，
