Visual cameras can be blinded by the sun too. But radar can't.
Engineering safety is typically done through redundancy. Tesla has no redundancy in their self driving system; it's all visual. If it's vision gets obscured by weather or darkness or the sun, it is essentially driving blind.
If one or more of the multiple cameras are obscured, the car will alert you to the degraded state. If conditions are particularly bad like in a snowstorm, FSD will refuse to engage. It doesn't drive blind.
Visual cameras can be blinded by the sun too. But radar can't.
Engineering safety is typically done through redundancy. Tesla has no redundancy in their self driving system; it's all visual. If it's vision gets obscured by weather or darkness or the sun, it is essentially driving blind.