# Is there something about the light from a laptop that blinds flies? **URL:** \ **Category:** Factual Questions\ **Created:** [July 22, 2014, 3:04am UTC](https://boards.straightdope.com/t/is-there-something-about-the-light-from-a-laptop-that-blinds-flies/693717 "2014-07-22T03:04:16Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![dropzone](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dropzone/32/7515_2.png) [@dropzone](https://boards.straightdope.com/u/dropzone)\ **Post date:** [July 22, 2014, 3:04am UTC](https://boards.straightdope.com/t/is-there-something-about-the-light-from-a-laptop-that-blinds-flies/693717/1 "2014-07-22T03:04:16Z")
My laptop screen is the only light in my room. A little while ago there were [del]three[/del] four live flies in my room. As moths to a flame all [del]three[/del] four came to the laptop and, with no particular fly-killing prowess, I caught and killed them. They were so slow and stupid it was as if they couldn’t see my hand–one I picked up with my fingers before dispatching it. Does the light have anything to do with it? I assume they were swift and agile in daylight, but I didn’t save them to test them in the morning. ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [July 22, 2014, 4:49am UTC](https://boards.straightdope.com/t/is-there-something-about-the-light-from-a-laptop-that-blinds-flies/693717/2 "2014-07-22T04:49:11Z")
Flies are not blinded by the the light. They have no trouble with sunlight do they ? They are blinded by the dark, and slowed by the cold. They really do hide at night and only come out at day. Flies act like its dawn and move toward the light, as if they were exiting a cave or tree cavity. They sit in the the warm to warm up, in order to function better, and await proper dawn. You can tell flies don’t like the cold as go to hide in cool weather, the colder the weather the more desperate they are to go hide. I don’t think the light of the laptop will blind them, as its not really as strong as daylight. They seem to sit there as if they are looking for the exit… They may also be watching for predators coming in from the source of the light… ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [July 22, 2014, 5:09am UTC](https://boards.straightdope.com/t/is-there-something-about-the-light-from-a-laptop-that-blinds-flies/693717/3 "2014-07-22T05:09:13Z")
> [@Isilder](#): > > Flies are not blinded by the the light. They are, however, [according to the best of authorities](http://www.straightdope.com/columns/read/1120/in-blinded-by-the-light-what-exactly-is-the-lyric-following-the-title-phrase), cut loose like a deuce, another runner in the night. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [July 22, 2014, 5:56am UTC](https://boards.straightdope.com/t/is-there-something-about-the-light-from-a-laptop-that-blinds-flies/693717/4 "2014-07-22T05:56:25Z")
I’ve heard that many insects used the natural polarizing effect of sunlight to navigate. I wonder if the polarization of the light from a computer screen affects their senses. ---
**Author:** ![tullsterx](https://avatars.discourse-cdn.com/v4/letter/t/e9bcb4/32.png) [@tullsterx](https://boards.straightdope.com/u/tullsterx)\ **Post date:** [July 22, 2014, 3:17pm UTC](https://boards.straightdope.com/t/is-there-something-about-the-light-from-a-laptop-that-blinds-flies/693717/5 "2014-07-22T15:17:35Z")
Were you watching videos of funny cats on youtube at the time. . . Well, then they were transfixed. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [July 22, 2014, 8:34pm UTC](https://boards.straightdope.com/t/is-there-something-about-the-light-from-a-laptop-that-blinds-flies/693717/6 "2014-07-22T20:34:08Z")
The polarization suggestion might beat my guess: The screen is flickering. You don’t notice it, but the bugs might have problems. It could be messing up their visual system. ---
**Author:** ![dropzone](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dropzone/32/7515_2.png) [@dropzone](https://boards.straightdope.com/u/dropzone)\ **Post date:** [July 22, 2014, 10:56pm UTC](https://boards.straightdope.com/t/is-there-something-about-the-light-from-a-laptop-that-blinds-flies/693717/7 "2014-07-22T22:56:09Z")
I’ll go with the polarization/flickering idea. They have their own cat to stare at.