If you are using your phone in dark it might effect your eyes ,we previously told about flux that adds a reddish layer to protect your eyes while using computer
Android is a simple screen filter
that applies a reddish overtone to
your display so you won’t lose
your night vision.
It comes with 4 colour schemes
Dark — the standard gray filter dims light
without adding any color.
Midnight — a slight tinge of midnight blue
keeps the screen cooler during red
sunsets or sunrises.
Sunset — designed to limit the amount of
blue light that goes into your eyes to help
Red — designed for stargazers,
astronomers, and telescope enthusiasts to
help maintain your night vision.
It is available for 1$
If you are looking for a free alternative try twilight app