Final answer:
Vision can be affected by drugs and alcohol, making it especially difficult to distinguish distance because of the impaired function of the rods and cones in the eye that affects the clarity of images formed at various distances.
Step-by-step explanation:
Vision can be affected by drugs and alcohol making distance especially difficult to distinguish. Our vision depends on the eyes detecting light and forming images, which are interpreted by the brain. When under the influence of drugs or alcohol, the clarity of these images can be compromised. The rods in our eyes, which are responsible for night vision, peripheral vision, and motion changes, and the cones, which are responsible for central vision and color, may not function optimally. This can make producing images at a far point, which is the maximum distance at which the eye can see an object clearly, quite challenging. Consequently, it becomes difficult to determine how far away objects are, increasing the risk of accidents while driving, for example.
Conditions like myopia (nearsightedness) and astigmatism can further influence how well a person can see at a distance, even without the effects of intoxicants. Drugs and alcohol can exacerbate underlying vision problems, leading to an increased difficulty in distinguishing distance, among other visual impairments.