Have you ever been blinded by someone else’s headlights, or noticed that your own headlights are not illuminating the road directly in front of you? If all you can see is the foliage on the side of the road, or oncoming drivers are constantly flashing their high beams or honking their horn at you, most likely your headlights are misaligned and giving those other drivers an eyeful. They're easy to adjust with a few measurements and a screwdriver.

Steps

1
Level your car. Start by removing any excess weight from the trunk of the car. Also, ensure that the tire pressure in all tires is at the manufacturer's recommended levels. If possible, have somebody sit in the driver's seat, and that the gas tank is half-full. As well as this, check that your headlight aim adjustment wheel (if fitted) is at the zero position.

2
Position your car. On level ground, park 10 to 15 feet (3.0 to 4.6 m) from a dark wall or garage door, with the front of the car aimed at the wall. A paved parking lot or level driveway is best.
Bounce the car a couple times on all four corners to make sure the shocks are leveled.
Measure the distance to the ground from both headlights to ensure that the suspension itself is level.[1]

3
Turn the headlights on. Do not use your high beams or fog lights. Mark the horizontal and vertical center lines of the headlight beams with masking tape to make two T’s on the wall or garage door.

4
Make sure the lights are level. Place a carpenter’s level between the two marked center lines to see if they are even. If they are not even, use a tape measure to measure how far up the wall the lower mark is and lower the other center line marker to the same height. These center lines should be no higher than 3.5 feet (1.1 m) from the ground.

5
Back your car exactly 25 feet (7.6 m) from the wall or garage door. Don't estimate the distance! Use a tape measure to make sure you are the proper distance away from the wall. Turn off the headlights. Remove the trim ring from around the headlights and locate the adjusting screws. These screws are typically found adjacent to the headlight, though some manufacturers put the screws in the engine compartment, behind the the headlights. The horizontal adjuster and the vertical adjuster should be marked.
Always defer to the specs in the owner's manual—some manufacturers recommend different distances for proper adjustment. For example, Toyota recommends 10 feet (3.0 m) feet, Pontiac GTO recommends 15 feet (4.6 m), and Chrysler recommends 3 feet (0.9 m) for some models. For this reason, it's important to check your owner's manual and follow those guidelines.[2]
There should be one screw at the top of the headlight to adjust vertically and another screw to one side of the headlight to adjust horizontally, though some cars may feature adjustment bolts rather than screws.

6
Adjust each headlight separately. Block one with a sweatshirt or other object while adjusting and testing the other, since the light-bleed can make it difficult to distinguish one from the other. Have a helper sit in the driver's seat while you do the adjustments, to turn the lights on and off while you make the proper adjustments.[3]

7
Turn the upper screw or bolt to adjust the vertical field. Clockwise turns should raise the lights, while counterclockwise turns should lower the lights.
Turn the headlights on after adjusting and look at the light pattern on the wall. The top of the most intense part of the beam should be even with, or just below the center of the line of tape you made.
8
Turn the side screws or bolts to adjust the horizontal field. Now, you'll do basically the same thing with the right-left adjustment. The majority of the intense part of the beam should be to the right of the vertical line.

9
Test your alignment on the road. Take your car out for a test drive to make sure the headlights are adjusted properly. Readjust if necessary by repeating the above steps.
Tips
Rock the car after adjusting the headlights and re-check them against the wall or garage door. Some car owner’s manuals will suggest doing this after a headlight adjustment. Readjust if needed.
If your state DMV has a headlight alignment test, make sure you conform to, at least, state requirements.
Look for a small level attached to the top of the headlight. Some car manufacturers install these small levels to help with adjusting headlights. Acura and Honda are two models that usually include this built-in level. This will eliminate the need for a carpenter’s level.
Check your headlights every 12 months to make sure they are aligned.

Warnings

Misaligned headlights can impair both you and other drivers, who might be momentarily blinded by headlights that are aimed too high.
Take your car to a mechanic to have the headlights adjusted if you are unable to do so, especially if you know your headlights need to be adjusted.

Things You'll Need
Phillips screwdriver or socket
Masking tape
Tape measure
Carpenter’s level (if needed)

https://http-m-wikihow-com.0.freebasics.com/Adjust-Car-Headlights?iorg_service_id_internal=1565619690390248%3BAfpO88EUH8VwGV2g

thanks

@ detrovert thanks a million

how I wish this guide came last month..
I was at the verge of changing my headlights because it was bright looking from the outside at night but from the drivers view it was completely dull.
I googled :how to aim your headlights and fixed a 3 yr old problem that made me drive less at night..

thanks sir/ma

edit;mine needed an allen key,not screwdriver.