Subject: What Of Alhazens contributions to science were contributions to physics?

(9th grader) I am writing a report on Contributions to Physics during the 
Abbassid Caliphate. Abu Ali Hasan Ibn al Haitham, known to the western world as 
Alhazen, made significant contributions to physics during this period, but I 
cannot decipher what were contributions to physics and what were contributions 
to other sciences.  Are optics, astrology (if its considered astro-physics),  
parts of the eye, and rainbows part of physics? 

Re: What Of Alhazens contributions to science were contributions to physics?