I note that the planet which appears to have the largest angular diameter as seen from Earth is Venus.
Venus, our sister planet, comes closest to Earth, ranging from 9.7" to a whopping 66.0".
In astronomy " is the symbol for an arc second of angular diameter.
Since a normal human eye can resolve objects as small as about 28 arc seconds, it might be possible to see the shape of Venus when Venus is almost closest to Earth and appears as a very thin crescent at almost its maximum angular diameter, though that would seem to be at the very edge of visibility.
Humans with exceptional vision, at Venus’ closest approach, can barely discern its crescent phase without a telescope.
My copy of The Guinness Book of Astronomy Facts & Feats, Patrick Moore,second ediiton, 1979, 1983, says that Galileo was the first persons to observe the phases of Venus which were evidence for the validity of the Coppernican theory. And says:
(The phases had not previously been mentioned specifically, though exceptionally keeen-sighted people can see the crescent form with the naked eye.)
The phases of Venus are the variations of lighting seen on the planet's surface, similar to lunar phases. The first recorded observations of them are thought to have been telescopic observations by Galileo Galilei in 1610. Although the extreme crescent phase of Venus has since been observed with the naked eye, there are no indisputable historical pre-telescopic records of it being described or known.1
The extreme crescent phase of Venus can be seen without a telescope by those with exceptionally acute eyesight, at the limit of human perception. The angular resolution of the naked eye is about 1 minute of arc. The apparent disk of Venus' extreme crescent measures between 60.2 and 66 seconds of arc, depending on the distance from Earth.
Mesopotamian priest-astronomers described Ishtar (Venus) in cuneiform text as having horns which has been interpreted as indicating observation of a crescent. However, other Mesopotamian deities were depicted with horns, so the phrase could have been simply a symbol of divinity.1
so it is possible that some people have seen the planet Venus as more than a dot in the sky, and even seen its cresent phase.