Does reflection always occur when there is refraction?

Not always, no. If you have a material with a smooth variation of index of refraction, like in a graded-index (aka GRIN) lens, then you can bend the light as it passes through with without reflection. read more

The same two conditions that are necessary for bending the path of the line of students are also necessary for bending the direction of a light ray. Light refracts at a boundary because of a change in speed. There is a distinct cause-effect relationship. The change in speed is the cause and the change in direction (refraction) is the effect. read more

If you add up the field on the two sides of the bounday you find that whenever there is refraction there is always some reflection to balance it out. Total internal reflection only occurs when light is passing from a higher refractive index medium to a lower refractive index medium. The easiest way to see why it happens is described below. read more