How Many Light Years Far We Can See?

How many light years far can we see? 

Let's find it out.

Hmm... the farthest I have seen with my naked eyes is about 2.4 million light years ;-) .The Andromeda Galaxy (M31) is just visible to the naked eyes when at a very dark site.

Using optical aids (a telescope) it is possible to see hundreds of millions of light years.

Then a camera is added, to integrate the incoming photons, it is possible to “see” over 13 billion light years.