2018 4Runner headlight problem

New to the 4runner family ! Could someone please tell me why my headlights look like this ?

 

Looks like moisture intrusion.

 

I agree -moisture inside somehow.
Remove bulb holders and perhaps carefully remove bulbs with new clean rubber glove, place in a safe spot off truck.
Blow air into bulb holder openings on backside of headlamp fixture
I would use a camp style air mattress electric air pump. Either 12vdc or 115vac (Usually $20 at Big 5). They usually come with a small hose and various tips.
Then blow air in larger volumes. Make sure air has discharge/leaks to outside to purge moisture out.
Do this on a warm sunny day.
Inspect carefully for source of moisture entry.
Has the engine been washed?

 

Just moisture intrusion. Unfortunately this is pretty standard for aftermarket headlights. This is one reason I've stuck with OEM.

But, with a 2018 that had the old halogen style lights, going back to OEM might be a big downgrade for you though. Unfortunately good aftermarket headlights cost a ton... Still, I've heard great things about Morimoto