Most if not all of the excessively bright headlights are HID lights and as such have height sensors attached to the suspension (front and rear) which should keep the beam level correct, however "normal" lights have an internally adjustable levelling device whereby you can lower your headlights from the drivers seat. As a consequence of these brighter lights I will adjust them to the lowest permitted level on a test if they require adjustment. Most cars, at their first M.O.T. will have the lights set below the permitted level and will have had sine they were made, which is testament to a "good" PDI, only checked to see if they actually work and not about where they're aimed.
Another thing is poorly fitted bulbs (usually at Halfords - if they illuminate, they're OK) give an incorrect pattern and can dazzle drivers.
Nothing compared to these excessively bright lights, which whether correctly adjusted OR not, do blind you for a time simply because they are so bright.
Headlight cleaning devices are automatically operated when the lights are on when you operate the windscreen washers, so you don't have a choice of having dirt on your lights at all provided the level of washer fluid is above the take off point of the headlight system
Tony.
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