When observing at night, particularly if you are in a location away from city lights, it is important to preserve your night vision to help you see dim objects in the sky.
Our Galaxy has a Night Vision mode which reddens the user interface. Red light has lesser impact on dark adaptation than does white light.
To invoke the Night Vision mode, tap or click the Night Vision button on the toolbar. Tap it again to return to normal mode.
The Night Vision mode is not perfect. On LCD screens used in iPads and some iPhones, there is light leakage around the pixels. This small amount of white light can be seen as a glow coming off the screen, particularly when looking at it from the side at night. This light leakage will affect your dark adaptation. There is nothing Our Galaxy can do to prevent this.
Some of the newer iPhones use an OLED display. These do not suffer from the pixel leakage problem and the Night Vision mode will be more effective.
One solution to the light leakage problem is to cover the screen with a piece of red film. You can buy red cellophane and tape it over the screen. Alternatively, some companies sell red static cling vinyl that you can apply to the screen and peel off as needed. We particularly like the "Red Eyes Xtra Dark Cling” sold by Sirius Astro Products.
Even if you have an OLED screen, we still recommend covering the scren with a red film. This will let you use other apps at night that don’t have a Night Vision mode.
Note for Mac users: While the Night Vision mode will redden the Our Galaxy window on macOS, it won’t have an effect on the rest of the screen. For macOS computers, it is best to get a sheet of red plexiglass and affix it to the front of the screen so the entire interface is reddened.
On iOS, another possibility is to use the Accessibility Color Filters to turn the whole screen red. Apple might change this in the future, but for now you can open the Settings app and go to Accessibility > Display & Text Size > Color Filters. Turn Color Filters ON and then slide the Intensity and Hue sliders all the way to the right. This should color the display a deep red.
You can toggle the color filter off and on using the switch on this screen. You can also set up a shortcut to toggle it from the iOS control panel or via a triple tap. To set this up, go to Accessibility > Accessibility Shortcut, and select the Color Filters option.