Value chain · CLM-1338
In plain terms
A 1970 experiment found that microwave cataracts in dogs needed the lens to heat up: the same repeated doses that clouded a warm eye did nothing when the eye was kept cool.
The claim as recorded
A 1970 dog study exposed one eye to microwaves at a nominal 2.5 GHz and 5 W/cm2 incident at the cornea. A single exposure of 60 seconds was taken as the cataract threshold: 45 and 55 s caused no change, 65 s a faint delayed opacity, and 75 s an immediate dense opacity with a lid burn. Seven to ten repeated exposures at 50 to 75 per cent of the threshold time caused a dense cumulative cataract when the animal was at normal temperature. A single threshold exposure at normal body temperature raised the lens to a maximum of 52 C. The same exposures under hypothermia, which kept the lens near or below normal body temperature (38 C maximum), caused no cataract. The paper concludes that microwave cataract formation is, directly or indirectly, thermal, and finds no evidence for the proposed non-thermal cumulative effect.
Evidence behind this: T2, provisional until peer review confirmed (coord ruling 2026-10-03), a measured animal experiment in a journal with method stated; it permits "the 1970 paper measured Y". Fifteen dogs; one eye per exposure, contralateral eye as control.
Scope and limits
Only one power density was used, so the paper gives a time threshold at 5 W/cm2, not a power-density threshold. 5 W/cm2 is 500 times the then US 10 mW/cm2 guideline (our arithmetic); the paper says nothing directly about cataract risk at low densities over long periods. A random reflected field in a multimode cavity, not a plane wave. Long-term controls were followed for only 4 months. Small numbers (one or two animals per condition). Journal volume and peer-review status not confirmed from the pages held.
What it assumes
The cavity field gives a uniform 5 W/cm2 at the cornea as calibrated by calorimetry; a dog eye stands in for a human eye.
Where it comes from
PDF p.3 / printed 160: "nominal frequency of 2.5GHz"; power density "5watts/cm2 as measured by calorimetry"; fifteen dogs. PDF p.4 / printed 161: 45 and 55 s no effect, 65 s "feather" opacity, 75 s dense opacity; threshold "fixed at 60 seconds"; 38 C at the lens under hypothermia. PDF p.5 / printed 162: 52 C maximum after one threshold exposure in the normothermic eye; dense cumulative cataract in the normothermic eye, hypothermic lens "perfectly clear". PDF p.6 / printed 163: exposures under hypothermia "did not produce cumulative microwave cataracts"; cataractogenesis "is, directly or indirectly, a thermal phenomenon". PDF p.2 abstract: initiating mechanism "entirely thermal in nature".
Basis: W/cm2 incident at the cornea; seconds of exposure; degrees C intra-ocular
Related records
- Answers question
- QST-001 not published in this release
Cite this
energyaperture.com/c/clm-1338
CLM-1338, Energy Aperture, as of 1970-12.