Hello  Dear
I evaluated your concern in depth .
@ It is usually not common side effect to have 
constipation , but individual 
    case may notice it 
@ Recommendations for you :
 # temporarily stop Areds 2 , wait for 2 days if constipation relieved fine
    can take help of green leafy vegetables, whole grains, high fiber content,
    plenty of fluids , organic fruits to tackle constipation more better manner 
 #  once constipation is over , start Areds and if then constipation re  
     appear  that confirms your gut sensitivity to it 
Hope this will definitely help you .
Feel free to ask any future health related query anytime .
Thanks for using health care magic .
Regards .