* Transparent: This describes something that allows light to pass through it completely, so you can see clearly through it.
* See-through: This is a more informal and general way to describe something that allows you to see through it, regardless of the level of clarity.
* Translucent: This describes something that allows some light to pass through, but not enough for you to see clearly through it. You can still see shapes and shadows.
* Permeable: This word describes something that allows fluids or gases to pass through it. While not directly related to seeing through, it might apply if you are talking about a material that allows light to pass through due to its porous nature.
The best word to use will depend on the specific situation and the level of clarity you are describing.