So what, unconscious?
Interior camera could likely handle that (though it's nowhere near good enough or in a good position to judge if you're "paying attention"- but you don't need to be for L3)
I suppose sun glasses would still be an issue since it's not the right type of camera to see through them, but it doesn't need to be perfect- it's not like the CURRENT wheel sensor is perfect for detecting paying attention but they use it anyway.
It stops if you don't respond- but doesn't know how to "pull over safety" it just stops wherever it is right in your lane (and turns on hazzards IIRC)
IIRC requiring "can pull over safely on its own if human doesn't take over" is L4, not 3. 3 REQUIRES the human to be able to take over within some limited time period, just not immediately.
- Level 3 ("eyes off"): The driver can safely turn their attention away from the driving tasks, e.g. the driver can text or watch a movie. The vehicle will handle situations that call for an immediate response, like emergency braking. The driver must still be prepared to intervene within some limited time, specified by the manufacturer, when called upon by the vehicle to do so. You can think of the automated system as a co-driver that will alert you in an orderly fashion when it is your turn to drive. An example would be a Traffic Jam Chauffeur.[59]
- Level 4 ("mind off"): As level 3, but no driver attention is ever required for safety, e.g. the driver may safely go to sleep or leave the driver's seat. Self-driving is supported only in limited spatial areas (geofenced) or under special circumstances. Outside of these areas or circumstances, the vehicle must be able to safely abort the trip, e.g. park the car, if the driver does not retake control. An example would be a robotic taxi or a robotic delivery service that only covers selected locations in a specific area.
- Level 5 ("steering wheel optional"): No human intervention is required at all. An example would be a robotic taxi that works on all roads all over the world, all year around, in all weather conditions.
Yeah pretty much I just want to be able to read or watch a show/movie or play a game while the car drives me to work/back or wherever on the highway- L3 is good enough for that.