Which of the following is NOT a symptom of carbon monoxide poisoning?

Carbon monoxide poisoning presents with a variety of symptoms due to the gas's effects on the body's ability to transport oxygen. Dizziness, weakness, and nausea are all common symptoms associated with this form of poisoning. They result from the lack of oxygen reaching the brain and other vital organs, leading to cognitive and physical impairments.

In contrast, vision improvement is not recognized as a symptom of carbon monoxide poisoning. In fact, exposure to carbon monoxide typically leads to a decrease in visual acuity, among other neurological symptoms. This further underscores the nature of carbon monoxide as a harmful gas that creates serious health risks, emphasizing the importance of recognizing legitimate symptoms in order to seek timely medical assistance.