Throughout the Naruto fanbase, it is widely believed that the Uchiha have superior eyesight. That is incorrect. Nowhere in the series does it ever say that the Uchiha are born with better eyesight than any other person. Their eyesight is the same as any other person's.
It is only the clan's kekkei genkai ability, the Sharingan, that enhances an Uchiha's visual sight. The Sharingan enhances and improves the user's vision, allowing the user to see things that normal human eyesight could never detect. But it is only when the dojutsu is activated that an Uchiha's eyesight becomes better than a regular person's. Otherwise, their vision is just as good or bad as anyone else's. The Sharingan is genetic; 20/20 vision is not.
There is absolutely nothing backing the claim that the Uchiha are all born with innately superior vision. They are merely born with the genetic potential to awaken the Sharingan, which when activated gives them enhanced vision, as well as a ton of other abilities. More than one Uchiha have glasses, such as Sarada or that other unnamed Uchiha who attended the clan meeting, so an Uchiha can have poor eyesight just like anyone else. It makes sense for an Uchiha to need glasses, because they are human, and all the time people need glasses to correct their vision.
Sarada probably doesn't need her glasses when she activates her Sharingan, but her Sharingan is going to drain her stamina, so it makes more sense for her to not leave it constantly activated, as otherwise she would be constantly exhausted, especially with the Phase I Sharingan, which is less efficient and thus more draining in comparison to the later phases, which are probably more efficient in chakra usage.
Even Madara alluded to his eyesight being better than Hashirama's specifically because he had the Sharingan, or in his case, at least the potential to awaken the Shairngan. Either way Madara was directly attributed his superior vision to the Sharingan, not just some coincidence of being born with 20/20 vision.