Headlights issue help

[Hattan]

So for a week now my headlights been weird, I had one get weaker than the other which I was going to deal with but i didn’t get a chance to get to it. But it’s been switching from one getting weaker one the passenger side then after some drive cycles the left is strong right is weaker and then where I had a point last night where both got weaker to the point it looked like very dim and caused me to almost hit a deer(couldn’t use high beam as cars were on coming on the left side). What’s the issue with the light bulbs and how do I fix it? Thank you

 

[inuyasha-rules]

Could be a bad plug on the headlight. I've had to replace my passenger side twice, and driver side once in a year.

 

[Daw14]

Search out any grounds in the area ,a corroded ground will cause this exact issue.