Lamer L
Ophthalmology. 1983 Feb;90(2):156-61. doi: 10.1016/s0161-6420(83)34584-x.
The long-term effects of extended wear contact lenses (Perfilcon A [Permalens]) for myopia have been studied among 400 patients in a private clinic from December 1977 to September 1982. The drawbacks and possible complications were evaluated. With the exception of one case, no permanent modification of the cornea or ocular adnexa was found. The high rate of success among well-selected patients (without significant astigmatism or chronic infection of the eyelids) far outweighs the risks of radial keratotomy as it is known today. By and large patients opt for this method of optical correction once they are aware of its availability and remain with it despite the necessary frequent replacement of the lenses.