How can you observe the surface of the Sun through a telescope without endangering your eyes?

A dense sun filter should be put on the lens (not the eyepiece) of the telescope, making sure that it is fixed and does not fall off it. Another way is to project the image of the Sun onto a white screen mounted behind the eyepiece, while aiming at the Sun without looking through a telescope.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.