<prompt> Lens contains the oldest cells in-NucleusAnterior surface of lensPosterior surface of lensNucleo- coical junction  <response>: Nucleus is the central pa containing older fibres. Embryonic zone of nucleus embryonic nucleus contains oldest fibres. Coex contains the youngest fibres. Ref: Parsons 22nde p.26121ste p.256,257; Khurana 7the p.1854the p.167. 