You're right! A ray of light does bend when entering a glass block. This bending of light is called refraction.

Here's why it happens:

* Speed of light: Light travels at different speeds in different mediums. It travels slower in glass than in air.

* Angle of incidence: When light enters a denser medium (like glass) at an angle, one part of the wavefront enters the glass before the other. This causes the wavefront to change direction, bending the light ray.

Why we might think light doesn't bend:

* Normal incidence: If the light ray hits the glass block at a 90-degree angle (normal incidence), there is no bending. This is a special case.

* Small angle: If the angle of incidence is very small, the bending of the light ray is also very small and might not be noticeable to the naked eye.

Let me know if you'd like a diagram to help visualize this!