Refraction of Light: Is There No Refraction?

[AkshayPitt]

I understand that when light goes between air and water, refraction occurs (either towards or away from the normal). If the light going between air and water is already going in the same direction as the normal, is there no refraction (or a refraction angle of 0 degrees)?

Thank you.

 

[Bystander]

same direction as the normal

What is the sin of zero?

 

[AkshayPitt]

sin(0) = 0

Thanks a lot for your help!