Much confusion exists as to the value of ultraviolet rays in the treatment of infectious and other disorders of the eye. Brilliant results have been described in the neuropathic group of diseases, and particularly in the herpetic group, in which dendritic keratitis is outstanding. These observations have been made only in isolated cases or in small groups of cases such as reported or cited in discussions by Duke-Elder,1 Bernd,2 Post,3 Walker,4 Gifford,5 Green,4 Stock,6 Peppmüller7 and others. As far as I know, no definite experimental investigations have been made on the germicidal effect of ultraviolet rays on the virus of herpes.
On ordinary bacteria, the effect of ultraviolet irradiation is well known. It has been clearly shown by Verhoeff8 that ultraviolet rays cannot under any conditions destroy bacteria within the cornea, even when the latter is perfectly transparent, without