Thanks to all who responded. In the days subsequent to the original post with the question, I was able to find several research papers on the subject. These papers have been published in the past 20-40 years (including some from ~ 2009). It's always nice to read the primary sources, so that you can see the methodology, results, and make your own judgement on the such things as statistical significance, etc.
So, in case somebody is interested, - I am happy to share my short summary on the subject (and I'd be happy to send references to the original articles, should there be interest). The question of the long- and short-term effects of the flash-light and strong ambient light still requires comprehensive studies: there are no results showing that there is no harm at all, (I haven't found those, and several research articles say that explicitly) while several research articles show some specific indications that the may be certain negative effects. To quote one of the earlier articles' conclusions (Moseley MJ, Fielder AR, "Light toxicity and the neonatal eye", Clinical Vision Sciences, 3, 75-82 (1988)): "Exposure to intense and/or prolonged illumination may pose an ocular hazard for the neonate. Direct evidence from studies involving human subject is sparse, although a wealth of eidence suggesting thar the infant may be at risk is available from te animal literature." However, there are studies (several of this articles are dated after 1988) that have shown: 1. The morphology of the eyes of newborn infants is different, and is changing rapidly (i.e. "gestational age", the age from conception). 2. In particular, - while the sensitivity (in the sense of negative effects) to the red end of the spectrum is less pronounced, blue part of the spectrum has a stronger effect. (Hence, I would expect that flash's sub-UV and UV components would may have stronger effect.) 3. At least one paper talks about the long-term decrease of how acute vision is in the grownups due to exposure to bright light shortly after birth. 4. All the negative effects described above are more pronounced with primis. ... And as far as I can see myself, at least during the first week, kids react to the photo flash, and even a regular CFL or fluorescent tube light even when their eyelids are closed. So, - for my own child (and if I'd get to photograph any of the friends' children), I'd try to avoid a flash for the first 2-4 weeks, especially while the eyes are open. Igor > From [email protected] Mon Jul 11 00:40:11 2011 > Date: Mon, 11 Jul 2011 00:40:09 -0400 (EDT) > From: Igor Roshchin <[email protected]> > To: [email protected] > Subject: newborns and flash > > > Hi All, > > I remember reading about the fact that the newborns either do not have > as fast reaction of the pupil to the bright light, as most humans do, > or their retina is too fragile, and that until some age (N weeks), a > photo flash (especially with repeated use) might cause some damage to > the retina. I cannot seem to find any "solid" source for that now, and in > particular, I don't remember how many weeks that lasts. > > I've found a bunch of "anecdotal" evidences that are not serious > (e.g. "I was photographing my newborn son with a flash, and > his vision now, past 15 years, is fine."), but I cannot find > any published research on this topic. > (I did find a paper from 1982 saying that the newborns have central > part of the retine underdeveloped, and they have mostly pereipheral > vision. And I found a paper from 80s showing that after the 34th week > of gestation the pupil does change it size in response to [some] light.) > > I was wondering if any of PDMLers either has a reference to the source > of information or knows a children's ophtalmologist with experience > about these question. > > Igor > > -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
