The transmission of blue-green argon laser light (lambda = 488 nm and lambda = 514.5 nm) through clear healthy corneae was measured by means of a photodiode implanted into whole human donor eyes. The mean corneal transmission in seven eyes (donor age: 32-84 y) was 93.2 +/- 3.2% S.D., range 87-98%. The time between death and measurement ranged from 3.5 to 16 hr. These results indicate that hardly any correction for light loss in a healthy cornea is required in fluorophotometric results obtained with the use of fluorescein (lambda max.exc. = 489 nm, lambda max.em. = 514 nm).