Lens is derived from: (Repeat)

Ans: A (Surface ectoderm) Ref: Gray's Anatomy, 40th edition. pg. 700Explanation:Embryology of EyeThe developing eye appears in the 22 days embryo as a pair of shallow grooves on the sides of the forebrainOptic vesicle forms as a out pocketings of the forebrain which comes in contact with the surface ectodermThe optic vesicle begins to invaginate to form optic cupThe cells of surface ectoderm initially in contact with the optic vesicle begin to elongate and form the lens placode which develops into lens vesicleThe lens develops from the lens vesicleThe posterior cells become filled with a very high concentration of proteins (crystallins) which render them transparent; they also become densely packed within the lens as primary lens fibres.Cells at the equatorial region of the lens elongate and contribute secondary lens fibres to the body of the lens in a process which continues into adult lifeThe polarity and growth of the lens appear to depend on the differential distribution of soluble factors which promote either cell division or lens fibre differentiation and are present in the anterior chamber and vitreous humour respectively.Congenital cataracts can be associated with mutations in genes that encode structural lens proteins, particularly crystallin proteins. (See the following table)