UVB Is primarily absorbed in front part of your eye (the cornea and the lens)
– so probably no additional problem about looking at UVB on the retina – not a focus problem
World Health Organization
Worldwide approximately 18 million people are blind as a result of cataracts,
of these 5% of all cataract related disease burden is directly attributable to UV radiation exposure.
Cataract Wikipedia
A study among Icelandair pilots showed commercial airline pilots are three times more likely to develop cataracts than people with nonflying jobs. This is thought to be caused by excessive exposure at high altitudes to radiation coming from outer space, which becomes attenuated by atmospheric absorption at ground level.
Supporting this theory is the report that 36 of the 39 astronauts involved in high-radiation-mission, such as the nine Apollo missions to leave Earth orbit, have developed early stage cataracts that have been shown to be caused by exposure to cosmic rays during their trips.
A review of the epidemiologic evidence linking ultraviolet radiation and cataracts.
Dev Ophthalmol. 2002;35:21-31.
McCarty CA, Taylor HR.
Centre for Eye Research Australia, University of Melbourne, Australia. mccartyc at mmrf.mfldclin.edu
BACKGROUND/AIMS: Cataract is the most common cause of blindness in the world and there are currently no strategies to prevent it. The aim of this paper is to review the epidemiologic evidence linking ultraviolet (UV) radiation and cataract.
METHODS: Published epidemiologic research articles on UV and cataract were reviewed against the epidemiologic criteria for causality: biological plausibility, strength of the association, specificity, experimental evidence, temporal sequence of events, dose-response relationship, and consistency.
RESULTS: The majority of the 22 epidemiologic studies reviewed met most of the epidemiologic criteria for causality and support an association between UV-B and the development of cortical cataract and perhaps posterior subcapsular cataract.
CONCLUSIONS: The epidemiologic data justify the implementation of public health campaigns to raise public awareness of the risk of cortical cataract due to ocular UV-B exposure. Future researchers should be careful to avoid potential bias by measuring personal ocular UV exposure and by quantifying cataract carefully.
PMID: 12061276
Influence of Exposure Time for UV Radiation–Induced Cataract – Oct 2000
Marcelo N. Ayala, Ralph Michael and Per G. Söderberg
From St. Erik’s Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
PURPOSE. It is believed that for a certain ultraviolet radiation (UVR) exposure, the biologic effect depends on the product of irradiance and exposure time (the reciprocity Bunsen–Roscoe law). The purpose of this study was to investigate the validity of the reciprocity law for UVR-induced cataract.
METHODS. Two experiments were conducted. In the first one, 100 Sprague–Dawley rats were exposed to UVR divided into five groups according to exposure time: 7.5, 15, 30, 60, and 120 minutes. In the second experiment, 80 Sprague–Dawley rats were exposed to UVR divided into four groups according to exposure time: 5, 7.5, 11, and 15 minutes. All the animals were unilaterally exposed to the same dose of UVR (8 kJ/m2) in the 300-nm wavelength region. One week after exposure both lenses were removed to measure the intensity of forward light scattering and for microphotography. Groups were compared by evaluating the difference between exposed and nonexposed eyes.
RESULTS. The group exposed to UVR for 5 minutes had the lowest intensity of forward light scattering. The highest intensity of forward light scattering was found in the group that was exposed for 15 minutes. With longer exposure intervals, the intensity of forward light scattering decreased as the exposure time increased. No difference in intensity of forward light scattering was found between the groups exposed for 60 and 120 minutes.
CONCLUSIONS. Exposure time strongly influenced cataract formation after low-dose UVR. In this model of UVR-induced cataract, the photochemical reciprocity law was modulated by a biologic response.
PDF is attached at the bottom of this page
Note: This study indicates that some UVB does get to the retina.
Note: This study shows that the eye adapts to short term intense UV radiation.
This does not allow making any prediction of the effects for low-level UVR over a long period of time.