What Causes Seeing Yellow Spots After Adderall Intake For ADHD?

Hi, I am a 43 year old female and I was recently diagnosed with ADHD and was prescribed 20 mg of Adderall xr once a day. It is helping with the ADHD beautifully, I can concentrate better, I am not as hyper. I even talk and walk more slowly which is good because I usually leave people in the dust so to speak. Now to the point, since I started taking adderall I some times see yellow spots especially when I stand up to quickly. They are not constant and do go away. Is this a potential side effect of adderall and is it a cause for concern?