The answer was already addressed by @sabbahillel. I would like to point out though that scientists use the term 'visible' universe to not mean 'what you can see with your naked eye'. Scientists use this term to describe the universe in terms of the speed of light - i.e. the maximum physical limits light can travel.
The term visible thus is misleading. It does not at all refer to stars you can 'see' with your naked eye, but rather the whole gamut of the universe as far as light can travel.
The observable universe is a spherical region of the Universe comprising all matter that can be observed from Earth at the present time, because electromagnetic radiation from these objects has had time to reach Earth since the beginning of the cosmological expansion. There are at least 2 trillion galaxies in the observable universe. Assuming the Universe is isotropic, the distance to the edge of the observable universe is roughly the same in every direction. That is, the observable universe has a spherical volume (a ball) centered on the observer. Every location in the Universe has its own observable universe, which may or may not overlap with the one centered on Earth.
The word observable in this sense does not refer to the capability of modern technology to detect light or other information from an object, or whether there is anything to be detected. It refers to the physical limit created by the speed of light itself. Because no signals can travel faster than light, any object farther away from us than light could travel in the age of the Universe (estimated as of 2015 around 13.799±0.021 billion years) simply cannot be detected, as they have not reached us yet. Sometimes astrophysicists distinguish between the visible universe, which includes only signals emitted since recombination—and the observable universe, which includes signals since the beginning of the cosmological expansion (the Big Bang in traditional physical cosmology, the end of the inflationary epoch in modern cosmology).
In any event, the Torah tells us that Hashem told Avrohom Avinu to look up at the stars and to theoretically count them. The commentators (includ. Rashi) explain that Avrohom Avinu was told to look at his astrology charts to show him that Avrohom Avinu and his family would be above the stars, i.e. they would not be governed by the natural order of the world, but be able to break beyond that.)
On a very simple level then, Avrohom Avinu would have seen approximately 6000 stars give or take a few hundred, depending on his location and visibility (see Sky and Telescope).
So while it is a nice thought that the number of stars is 10^22, it doesn't seem to me that this figure was part of the equation. Avrohom Avinu did not have a hubble-space telescope to tell him the number of stars in the observable universe!