THE CLINICAL problem posed by opacification of the cornea stimulated an early interest in the factors responsible for transparency of this tissue and the possible explanations for its striking dissimilarity to the sclera. The most recent attack on this problem has been made by Cogan and Kinsey,1 who reviewed the pertinent work before their time. These authors emphasized the water content of the cornea as the chief determining factor in the transparency of this tissue and as responsible for the optical difference between cornea and sclera. According to their concept, the cornea is endowed with a dehydrating mechanism (in the form of semipermeable endothelium and epithelium) to keep down its water content. When this mechanism fails, swelling, and therefore opacification, occurs. The sclera, on the other hand, is said to be opaque because of the absence of any such mechanism.
While studying swelling of the cornea, we had ample
HART WM, CHANDLER BF. THE CORNEAII. Factors Affecting the Transmission of Visible Light by the Fibrous Tunic of the Eye. Arch Ophthalmol. 1948;40(6):612-623. doi:10.1001/archopht.1948.00900030627003