In transparent matirials it is known that when light going through it ,photones speed in the matirial would be smaller than in a vaccum. When the light refractioning, the photones transfer from one transparent media to another (for example- Vaccum to water). The photones during the process changing their diraction manifested by the change between the hit angle and the refraction angle. From those data`s: Does the photones get accelration because the changing of the amount and direction of the speed during the refraction, does according to the second Newton law there is a force that making photones get accelration while they transfer from one transpernent media to another? could it be simillar to the general reatvility that the light getting curved next to stars because the space getting curved due to the gravitation influence from the star? Or maybe it could be because of the qualities of the light - zero mass photones, and dual particle-wave behavior?