The watery humour of the eye is a limpid water that fills all the space between the cornea of the eye, and the anterior part of the crystalline humour. This space is divided into the anterior and posterior chambers; the first and larger division is betwixt the cornea and the iris. The second is betwixt the iris and the crystalline humour. The vessels which furnish this fluid are too small to be described. If discharged by a wound, it is restored in two or three days. In old age it is not so limpid, and this is one cause of obscure sight. The chief uses of it seem to be to distend the cornea, so that the rays of light may be duly refracted in passing to the retina; and for the iris to float loosely in, whereby its actions maybe easily performed. It has been supposed to be much lighter than distilled water; but M. Chevenix found its specific gravity to be 10053. In the eyes of sheep the aqueous humour is 10090, and it contains, in very-minute proportions, albumen, gelatine, and muriat of soda. See Oculus.