They're definitely not interchangeable. If you start saying I am seeing instead of I can see, people will notice you're talking like a foreigner. I can't explain how it works grammatically, but Chandler's use of the continuous here serves to convey the question: "do you the same thing I see?" See here for a similar use of see in the present continuous.
As far as I know it's ungrammatical to use the verb form "seeing" when perception is involved - do you mean specifically the gerund seeing, or any use of to see? Either way, it sounds wrong to this US English speaker: we use "seeing" to mean "perceiving" all the time.
grammar - When is it ok to use "seeing"? - English Language Learners ...
It felt really nice seeing all the things fall together into place. Vs It felt really nice to see all the things fall together into place. Is this just an infinite- gerund thing? Or are the mean...
I'm seeing exactly what you're trying to do. Move the exactly. Then both are correct. In fact, you can use the present simple or continuous. It depends on your intention.
Right now I am looking at the board. I see/am seeing some words on the board. Would you possibly readily or simply tell me which one? And why?
Which one must I use "see/am seeing" and what is your reason?
I’m not seeing anything now would be ok for Sarah to say; the present progressive, and more importantly, the now convey the contrast between the new and the previous states of affairs. For Alex, the simple I don’t see anything would be the most natural for (A). In any event, I think it less likely that Alex would use the now at all, because the now seems to suggest a contrast about what he ...