Does it sound natural?

[NewHopeR]

This phenomenon can be observed in blind person.

[5jj]

No.

I am afraid that I don't know what you are trying to say.

[NewHopeR]

No.

I am afraid that I don't know what you are trying to say.

Sorry.
It refers to "This phenomenon can be observed in blind people/the blind."
Now please edit it.

[NewHopeR]

The phrase "blind person" seems having been widely used (2 million hits in Google search):

How to Interact With a Blind Person

[emsr2d2]

A blind person = singular
Blind people = plural
The blind = collective noun

Whatever this phenomenon is, you would need to say:

This phenomenon can be observed in blind people.
This phenomenon can be observed in a blind person.
This phenomenon can be observed in the blind.

Without knowing the context, it's impossible to know which (if any) is correct.

[5jj]

Sorry.
It refers to "This phenomenon can be observed in blind people/the blind."
Now please edit it.

That's fine.

The phrase "blind person" seems having been widely used (2 million hits in Google search):

You can find anything you want by going to google. That does not prove it is acceptable. The link you provided is called 'How to interact with a blind person'.