Note: This study found no significant biological effects under its experimental conditions. We include all studies for scientific completeness.
Absence of Ocular Pathology after Repeated Exposure of Unanesthetized Monkeys to 9.3-GHz Microwaves
No Effects Found
R.D. McAfee, A. Longacre Jr., R.R. Bishop, S.T. Elder, J.G. May, M.G. Holland, R. Gordon · 1979
Monkeys exposed to intense 9.3 GHz microwaves showed no eye damage, but study limitations prevent conclusions about everyday wireless exposure.
Plain English Summary
Summary written for general audiences
Researchers exposed 12 monkeys to 9.3 GHz microwave radiation at 150 mW/cm² for 30-40 sessions, then monitored them for one year. No eye damage or cataracts developed despite direct facial exposure. This study examined whether high-frequency microwaves cause immediate eye injury at power levels far exceeding typical consumer devices.
Cite This Study
R.D. McAfee, A. Longacre Jr., R.R. Bishop, S.T. Elder, J.G. May, M.G. Holland, R. Gordon (1979). Absence of Ocular Pathology after Repeated Exposure of Unanesthetized Monkeys to 9.3-GHz Microwaves.
Show BibTeX
@article{absence_of_ocular_pathology_after_repeated_exposure_of_unanesthetized_monkeys_to_g5014,
author = {R.D. McAfee and A. Longacre Jr. and R.R. Bishop and S.T. Elder and J.G. May and M.G. Holland and R. Gordon},
title = {Absence of Ocular Pathology after Repeated Exposure of Unanesthetized Monkeys to 9.3-GHz Microwaves},
year = {1979},
}Quick Questions About This Study
No cataracts developed in 12 monkeys exposed to 9.3 GHz microwaves at 150 mW/cm² over 30-40 sessions and monitored for one year. This power density is approximately 750 times higher than typical cell phone exposure levels.
The 9.3 GHz frequency is higher than most cell phones (typically 0.8-2.7 GHz), and the 150 mW/cm² power density used was roughly 750 times more intense than holding a phone to your head.
Researchers needed conscious, unrestrained subjects to study realistic exposure scenarios. Training monkeys to voluntarily position their faces in the microwave beam allowed examination of eye effects without anesthesia complications that might mask radiation damage.
One year may detect obvious damage like cataracts, but subtle cellular changes or effects requiring longer development periods could be missed. Some radiation effects take years or decades to manifest clinically.
While no acute eye damage occurred at very high exposures, this doesn't guarantee safety from chronic, lower-level wireless exposures. The study's limitations prevent drawing conclusions about everyday device safety.