Since there are a large number of telescopes that are used to perform different functions, the distance that a telescope can see varies. It just merely depends upon the type of telescope being used. Just because a telescope may not see as far as another telescope, this does not mean it is a worse telescope because its function may be different.
Usually, you can see from a telescope for about 2.5 million light years, but it also depends upon how well the person’s eyes are who is using the telescope. If the person has poor eyesight, then they won’t see as far but it has nothing to do with the telescope. Usually, people can see the stars in the sky and they are 10,000 light years away.