What happens when light travels from one medium to another with a different index of refraction at a 0 degree angle of incidence?

light will travel in a straight line undeviated. Thus, there will be no refraction.

Explanation:

If the light hits the interface at angle equal to zero, then light movement is perpendicular to the plane of the second medium. And it will pass through undeviated. Therefore, the angle of refraction will also equal to zero. That is, there is no refraction.

in this image, you can see solar radiation going through ocean water.

no image, but probably absorption