Vision can be affected by drugs and alcohol making, especially difficult to distinguish
a) lightb) colorsc) distanced) shapes

B) Colors

Explanation:

The alcohol and drugs can blur one's vision. This is going to affect one's driving ability or skills. These substances can slow down the ability to focus, causes double vision, and the person is not able to distinguish color. The person will not be able to observe and understand the traffic signals, signs and roadways markings. Hence, alcohol and drug consumer in heavy dose are susceptible to accident.