Dim lights after battery and alternator replacement

Hi, i recently had my battery and alternator replaced and had my car in for a free winter check at the garage at the same time, which included battery and light check.

I also had a free winter check when I got my tyres done at a separate garage.

Both results came back OK.

However I noticed tonight my headlights seemed alot less brighter than normal and I actually pulled over go make sure they were on and from the outside thry looked fine.

Pulling up behind cars etc to see the reflection feels different I'm terms of the light feeling dimmer and less bright.

Is it a case for new bulbs or is there something underlying? I

Thank you