I do recall a few instances where the FAs explicitly requested the shades to be open on takeoff. It makes perfect sense. Without the horizon as a reference, disorientation is common when attempting to exit the plane, which might be upside down. Surprisingly, gravity offers minimal cues in such a situation.

BTW (and please don't hold this non sequiter too much against me), the same logic applies to prison construction. It is one of the reasons that windows are very high, or non-existent, in maximum security cells, exercise areas, etc. ... the lack of a horizon reference for extended periods has been shown to place escaping prisoners at a momentary disadvantage.