Structural component of eye lens gap junctions. Gap junctions are dodecameric channels that connect the cytoplasm of adjoining cells. They are formed by the docking of two hexameric hemichannels, one from each cell membrane. Small molecules and ions diffuse from one cell to a neighboring cell via the central pore. A hemichannel or connexon is composed of a hexamer of connexins. A functional gap junction is formed by the apposition of two hemichannels (PubMed:30542154). Forms heteromeric channels with GJA3 (PubMed:30542154). Detected in eye lens (at protein level) (PubMed:30542154). Eye lens (PubMed:8654111). Belongs to the connexin family. Alpha-type (group II) subfamily.