CRYBB1 encodes crystallin beta B1, a major structural protein component of the vertebrate eye lens 1. The gene is located on human chromosome 22.2-q12.1 and is closely linked to other beta crystallin genes 1. CRYBB1 functions as a structural constituent of the eye lens and plays a critical role in lens development and visual perception. The protein exhibits bidirectional transcriptional regulation, with CRYBB1 and the adjacent CRYBA4 gene frequently co-transcribed simultaneously from the same allele during lens fiber cell differentiation 2. Disease-wise, mutations in CRYBB1 cause autosomal dominant and recessive congenital cataracts. Several pathogenic mutations have been identified, including novel missense mutations c.209A>C (p.Q70P) 3, c.279C>G (p.S93R) associated with cataracts and microphthalmia 4, and c.755A>G (p.Lys252Arg) causing autosomal recessive cataracts 5. Interestingly, CRYBB1 expression is upregulated in diabetic retinopathy in males 6, and the gene has been implicated in neurological disorders including schizophrenia 7, suggesting broader roles beyond lens function. These findings establish CRYBB1 as essential for normal lens development and highlight its clinical significance in inherited eye diseases.