<p>This is called the <strong>Averted vision</strong>. It involves not looking directly at the object, but looking a little off to the side.</p>

<p><strong>How does it works?</strong></p>

<p>Because the retina is less sensitive at the center, and this is very remarkable on the very faint objects (like nebulas or galaxies)</p>

<p>This is a common technique used by astronomers.</p>

<p>More info <a href="http://oneminuteastronomer.com/86/averted-vision/" rel="nofollow noreferrer">here</a></p>

<p><strong>How to make the most of Averted vision?</strong></p>

<p>To maximise the effects of your Averted Vision, you first need to know which eye is your <strong>dominant eye</strong>. To do so:</p>

<ul>
<li>Point with your finger a distant object</li>
<li>Then blink an eye, then the other eye.</li>
<li><strong>The eye in which your finger is perfectly aligned with the object is your dominant eye</strong>.</li>
</ul>

<p>Then, for the best Averted vision:</p>

<ul>
<li>Look at the <strong>top-right</strong> of the object if your dominant eye is the <strong>right</strong> one</li>
<li>Look at the <strong>top-left</strong> of the object if your dominant eye is the <strong>left</strong> one</li>
</ul>

CC BY-SA 3.0
2017-08-19T09:22:42.647Z
I tried to find out which eye is dominant with that test, but it depended on which arm I used for pointing. The [Miles test](https://en.wikipedia.org/wiki/Ocular_dominance#Determination) worked for me.
Glorfindel
CC BY-SA 3.0
2017-08-18T13:59:20.870Z
2017-09-05T12:36:12.947Z
2017-09-05T12:36:12.947Z
Matthieu Charbonnier
<p>The effect you describe is called "averted vision".   It works because the center of the retina is optimized for details.  We use it for reading and anything that needs sharp vision.   The other parts of the retina are more sensitive to light and and motion but not to detail</p>

<p>Digital cameras are like this too.   Having many tiny pixels makes for a sharp image but the small pixels are less sensitive to low light and create more noise or grain in the image.  A digital camera is more sensitive to light if the pixels are physically larger but of course then you can have fewer of these in a same size sensor</p>

<p>The eye in effect has smaller "pixels" that are closer together but less sensitive to light in the center of the visual field and larger more sensitive "pixels" in the off center areas.   So, by looking off to the side you can cause the image of the nebula to fall on the part of the retina that is more sensitive to light.</p>

CC BY-SA 3.0
2017-08-18T19:41:48.427Z
2017-08-18T19:41:48.427Z
user3150208
<p>"Averted vision" is a nice term, and perhaps expertly technical as well. It's the same principle we are taught as shooters/small arms handlers to utilize for night-work when enhanced vision equipment is not available; we simply know it as a function of our peripheral vision, right up there with using the same visual technique to more easily detect motion - <em>especially</em> in a darkened environment. The phenomenon is due to both the distribution and the disparity in numbers of rods versus cones within the human retina. In any event, it's pretty cool once you get used to using it to your advantage :-) </p>

CC BY-SA 3.0
2017-08-18T21:19:28.327Z
This seems to be a comment on one of the other answers, not an answer itself. See [help] for more on how Stack Exchange works; it is not a forum.
chirlu
CC BY-SA 3.0
2017-09-10T07:52:51.993Z
@chirlu - He doesn't have enough rep points to post a comment.
iMerchant
CC BY-SA 3.0
2017-09-10T09:24:32.223Z
@iMerchant: Indeed. However, when you don’t have the privilege to comment, you should not evade by writing a non-answer. You can, however, write a (real) answer to any question and thereby get the reputation needed to comment. All this is explained in the help center that I pointed to.
chirlu
CC BY-SA 3.0
2017-08-18T20:54:27.147Z
2017-08-18T21:03:55.993Z
2017-08-18T21:03:55.993Z
John
<p>I have a 6cm aperture newtonian refractor telescope through which I saw the Orion Nebula yesterday night. As all you can hope with a telescope of such a small aperture, I saw some faint cloudy structure, but when I looked away from the cloud through the telescope it appeared to be more distinct and dense. Why is it so?</p>

CC BY-SA 3.0
2017-08-18T15:36:16.833Z
I focused my eyes away from the cloud...
Ajinkya Naik
CC BY-SA 3.0
2017-08-18T19:21:15.263Z
Are you sure you got the units right? 60 cm aperture is far from small.
Dan Mašek
CC BY-SA 3.0
2017-08-19T11:26:36.697Z
whoops....XD i always make the same mistake again and again its 60mm or 6cm
Ajinkya Naik
CC BY-SA 3.0
2017-08-19T15:07:27.777Z
This might explain it: http://hyperphysics.phy-astr.gsu.edu/hbase/vision/rodcone.html
flawr
<observational-astronomy><orion>
Why does the cloud of Orion Nebula appear more distinct when I am not directly looking at it?
Ajinkya Naik
# Why does the cloud of Orion Nebula appear more distinct when I am not directly looking at it?

(Asked by: username_0 on 2017-08-18)

I have a 6cm aperture newtonian refractor telescope through which I saw the Orion Nebula yesterday night. As all you can hope with a telescope of such a small aperture, I saw some faint cloudy structure, but when I looked away from the cloud through the telescope it appeared to be more distinct and dense. Why is it so?

**Tags:** observational-astronomy, orion
> **Comments:**
> **username_0**: I focused my eyes away from the cloud...  
> **username_1**: Are you sure you got the units right? 60 cm aperture is far from small.  
> **username_0**: whoops....XD i always make the same mistake again and again its 60mm or 6cm  
> **username_2**: This might explain it: http://hyperphysics.phy-astr.gsu.edu/hbase/vision/rodcone.html  

---

## 3 answers

### Answer by username_3 on 2017-08-18. Score: 17

This is called the **Averted vision**. It involves not looking directly at the object, but looking a little off to the side.

**How does it works?**

Because the retina is less sensitive at the center, and this is very remarkable on the very faint objects (like nebulas or galaxies)

This is a common technique used by astronomers.

More info [here](http://oneminuteastronomer.com/86/averted-vision/)

**How to make the most of Averted vision?**

To maximise the effects of your Averted Vision, you first need to know which eye is your **dominant eye**. To do so:

* Point with your finger a distant object
* Then blink an eye, then the other eye.
* **The eye in which your finger is perfectly aligned with the object is your dominant eye**.

Then, for the best Averted vision:

* Look at the **top-right** of the object if your dominant eye is the **right** one
* Look at the **top-left** of the object if your dominant eye is the **left** one

> **Comments:**
> **username_4**: I tried to find out which eye is dominant with that test, but it depended on which arm I used for pointing. The [Miles test](https://en.wikipedia.org/wiki/Ocular_dominance#Determination) worked for me.  

---

### Answer by username_5 on 2017-08-18. Score: 3

The effect you describe is called "averted vision". It works because the center of the retina is optimized for details. We use it for reading and anything that needs sharp vision. The other parts of the retina are more sensitive to light and and motion but not to detail

Digital cameras are like this too. Having many tiny pixels makes for a sharp image but the small pixels are less sensitive to low light and create more noise or grain in the image. A digital camera is more sensitive to light if the pixels are physically larger but of course then you can have fewer of these in a same size sensor

The eye in effect has smaller "pixels" that are closer together but less sensitive to light in the center of the visual field and larger more sensitive "pixels" in the off center areas. So, by looking off to the side you can cause the image of the nebula to fall on the part of the retina that is more sensitive to light.


---

### Answer by username_6 on 2017-08-18. Score: 0

"Averted vision" is a nice term, and perhaps expertly technical as well. It's the same principle we are taught as shooters/small arms handlers to utilize for night-work when enhanced vision equipment is not available; we simply know it as a function of our peripheral vision, right up there with using the same visual technique to more easily detect motion - *especially* in a darkened environment. The phenomenon is due to both the distribution and the disparity in numbers of rods versus cones within the human retina. In any event, it's pretty cool once you get used to using it to your advantage :-)

> **Comments:**
> **username_7**: This seems to be a comment on one of the other answers, not an answer itself. See [help] for more on how Stack Exchange works; it is not a forum.  
> **username_8**: @chirlu - He doesn't have enough rep points to post a comment.  
> **username_7**: @iMerchant: Indeed. However, when you don’t have the privilege to comment, you should not evade by writing a non-answer. You can, however, write a (real) answer to any question and thereby get the reputation needed to comment. All this is explained in the help center that I pointed to.  

---

