That regular astigmatism of the cornea is not always congenital, is clearly stated in some of our standard text-books on ophthalmology. Noyes (2d rev. ed., p. 111) states that "some rare cases of regular corneal astigmatism are acquired, but as a rule the affection is congenital." Schmidt-Rimpler (3d ed. p. 84) believes: "as a rule the affection is congenital." Berry (2d ed., p. 543) says of astigmatism: "The cause is mostly a difference in the curvature of different meridians of the cornea, a difference which may be congenital or acquired."
Hartridge (Refraction of the Eye, p. 122) expresses the view: "astigmatism is usually congenital, but may be acquired, and frequently there is some hereditary tendency." Henderson (Annals of Ophthalmology and Otology, Vol. v, p. 523) has reported one case of acquired regular corneal astigmatism. The literature bearing on acquired regular corneal astigmatism is certainly very limited. To be convinced that