Is it possible to see mercury transit "clearly" by the naked eye? I don't have a telescope but I'm interested in seeing events like eclipses and transits. 

I'll use the atmosphere as my big natural lens. So I'll watch the upcoming mercury transit at the sunset time where the sun looks bigger than usual. Will this make the black dot of mercury bigger or big enough to be obviously seen by the naked eye? I've never seen it before.

Event: https://www.timeanddate.com/eclipse/in/egypt/cairo
I did see the Venus transit before the Sun in 2004. 

I used no telescope, but of course I used proper solar eclipse glasses to protect my eyes. The black circle was small but clearly visible.

But Mercury is much smaller, the transit is not visible without a telescope. See Wikipedia.

Here an image of a Venus transit:



Here the much smaller Mercury:



The dark spots to the right and left are sunspots, Mercury is the very tiny black spot below the center of the Sun.

Images from Wikipedia.