A simple way that I understand it is:
without getting overly technical
The different colors of light refracts through the lenses at different angles
(Reason why we get a rainbow) All those colors enter from one end then exit according to their physics assigned angles)
the goal is to get them to line back up at your pupil on the other end
Red Blue Green being the main 3 colors of importance
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If one color is off, alignment, (They can use coatings or additional lenses to correct CA)
If one color is off, the image deteriorates either in contrast, focus, sharpness, quality, etc
This is very important for low light conditions, since you need all the help you can get and having as much of the color spectrum available for your eye assists in low light image quality
this is why paying more money for a scope usually yields better results in this area.
Think BSA vs Zeiss
there is no way that a $100 Walmart 6-24x BSA will have much attention paid to CA, and more attention instead simply on image magnification
High end coatings that aid in this area are expensive - (lets say $800 as the processes and rare elements used are also expensive)
again, another reason why even a decent $500 scope will not hold up to a March
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I have read mixed opinions regarding wearing glasses with using a scope
Some say it's ok, I tend to believe that extra medium the light has to pass through may deteriorate quality
If it works for you, go for it.
yet it is important to know that, The occular adjusts for whatever corrective your eye needs