When the wipers no longer clean well, the blades are probably worn or cracked. Replace them.
CAUTION
To prevent damage to the wiper arms and other components, do not try to sweep the wiper arm by hand.
NOTE
When raising both windshield wiper arms, raise the driver's side wiper arm first. When lowering the wiper arms, slowly lower the wiper arm from the passenger's side first while supporting it with your hand. Forcefully lowering the wiper arms could damage the wiper arm and blade, and may scratch or crack the windshield.
Replace the wiper blades using the following procedure.
CAUTION
To prevent damage to the windshield let the wiper arm down easily, do not let it slap down on the windshield.
CAUTION
Do not bend or discard the stiffeners. You need to use them again.
If the metal stiffeners are switched, the blade's wiping efficiency could be reduced.
So do not use the driver's side metal stiffeners on the passenger's side, or vice versa.
Be sure to reinstall the metal stiffeners in the new blade rubber so that the curve is the same as it was in the old blade rubber.
WARNING
Be sure to look over your shoulder before changing lanes:
Changing lanes without taking into account the actual distance of the vehicle in the convex mirror is dangerous. You could have a serious accident. What you see in the convex mirror is closer than it appears.
Mirror type
Flat type (driver's side)