The best answer for Vision can be affected by drugs and alcohol making ______ especially difficult to distinguish is
Alcohol and drugs may cause the iris to constrict and dilate at a much slower speed that is not at all suitable for its proper functioning.
It is important to make distinctions between different objects depending on lightness and darkness while driving.
This important ability, when driving at twilight, may be impaired due to alcohol and drugs.
Even a small amount of alcohol or drugs can increase the symptoms of a dry eye and cause problems in identifying colours easily.