# Reflection in monitor **URL:** \ **Category:** Factual Questions\ **Created:** [December 18, 2003, 10:27am UTC](https://boards.straightdope.com/t/reflection-in-monitor/219719 "2003-12-18T10:27:51Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Glix](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@Glix](https://boards.straightdope.com/u/Glix)\ **Post date:** [December 18, 2003, 10:27am UTC](https://boards.straightdope.com/t/reflection-in-monitor/219719/1 "2003-12-18T10:27:51Z")
I have a regular CRT monitor, fairly new. What puzzles me is the reflections I notice, particularly when the screen is black. There are two of them, one which appears to be further back is very crisp but has a strange purple hint to its colours, and the second one appears to be closer and is fuzzy, but seems to be correctly coloured. Anyone have any idea what I could be seeing? ---
**Author:** ![Desmostylus](https://avatars.discourse-cdn.com/v4/letter/d/c57346/32.png) [@Desmostylus](https://boards.straightdope.com/u/Desmostylus)\ **Post date:** [December 18, 2003, 10:45am UTC](https://boards.straightdope.com/t/reflection-in-monitor/219719/2 "2003-12-18T10:45:28Z")
You’re seeing reflections from both the inner and outer surfaces of the glass: two reflections. The difference in color comes from either a tint in the glass itself, or a colored coating on the glass, or a polarising effect in the glass. What brand, what model? ---
**Author:** ![Glix](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@Glix](https://boards.straightdope.com/u/Glix)\ **Post date:** [December 18, 2003, 10:48am UTC](https://boards.straightdope.com/t/reflection-in-monitor/219719/3 "2003-12-18T10:48:52Z")
ViewSonic E70f [http://www.viewsonic.com/products/crt\_e70f.htm](http://www.viewsonic.com/products/crt_e70f.htm) Hah, it even says the glass is anti-reflective… it lies! ---
**Author:** ![Nanoda](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Nanoda](https://boards.straightdope.com/u/Nanoda)\ **Post date:** [December 18, 2003, 10:56am UTC](https://boards.straightdope.com/t/reflection-in-monitor/219719/4 "2003-12-18T10:56:55Z")
My WAG? Some anti-reflection or UV coating. I used to get such a coating on my glasses, and they had that effect going. ---
**Author:** ![Desmostylus](https://avatars.discourse-cdn.com/v4/letter/d/c57346/32.png) [@Desmostylus](https://boards.straightdope.com/u/Desmostylus)\ **Post date:** [December 18, 2003, 11:10am UTC](https://boards.straightdope.com/t/reflection-in-monitor/219719/5 "2003-12-18T11:10:29Z")
And there’s the answer (from the link above): > [@](#): > > Anti-static, anti-reflection screen > > This screen **coating** refracts light while maintaining the highest quality displayed image. It’s a coating, probably two-layered. A colored layer that gives the effect **Nanoda** sees through coated glasses, and a diffusive layer on top. The diffusive layer (or it could even be a diffusive texture on the colored layer) gives the blurry reflection. You notice the reflections more when the screen in black, because the anti-reflection coating has done its job. If the reflection was just as bad _all the fucking time_, like it was on numerous older monitors that I used, that’d be a sign that it wasn’t an anti-reflection coating. 🙂 ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [December 18, 2003, 11:21am UTC](https://boards.straightdope.com/t/reflection-in-monitor/219719/6 "2003-12-18T11:21:58Z")
I wondered if it was front and back reflections, but I have another hypothesis: Chromatic aberration - the light entering your eye is refracted by the lens to differing degrees, depending on its wavelength (that’s why a prism splits white light into a spectrum) - Normally, our visual system compensates for a little chromatic aberration, but it is expecting to deal with a fairly wide spread of frequencies (i.e. lots of reference points). Is it possible that the two different coloured reflections, if they are made up of sufficiently narrow bands of wavelengths, to be refracted by differing amounts on entry to the eye and that the visual system, for lack of sufficient clues, is unable to fudge them into a single coherent image?