What symptom is NOT associated with blood agent exposure?

Vision impairment is not typically associated with exposure to blood agents. Blood agents, such as cyanide or carbon monoxide, primarily interfere with the body's ability to use oxygen at the cellular level. Symptoms of exposure to blood agents usually include nausea, rapid heart rate, and dizziness due to the body's physiological response to oxygen deprivation and the body's attempts to compensate for impaired oxygen transport.

The symptoms associated with blood agent exposure stem from their effect on the blood's ability to carry oxygen rather than direct damage to the visual system, which would be more characteristic of other types of agents or conditions. Thus, vision impairment is not a common symptom linked to blood agents, solidifying it as the right choice in this context.