Have you ever wondered why Xiao Ming's myopia doesn't affect your eyesight when you sit next to him, but if Xiao Hua gets "pink eye" and you accidentally use his towel, your eyes soon become red and swollen too? The secret lies inthe cause of the disease.
What Does "Health" Really Mean?
Healthis not merely the absence of disease or infirmity, but a state ofcomplete physical, mental, and social well-beingJust like the image on page 71 of your textbook showing children running across a green field, health is the full release of vitality in every aspect of life.
Infectious vs. Non-Infectious Diseases
- Myopiais a non-infectious disease. It is usually caused by prolonged improper eye use, resulting in an elongated eyeball axis or excessive lens curvature. It's a change in the body's own structure and does not involvepathogens.
- Viral conjunctivitis (pink eye)is a classic infectious disease. It is caused by external "pathogenic viruses." These viruses are pathogens that can spread from person to person.
Key Takeaway
Only diseases caused bypathogens(bacteria, viruses, parasites, etc.) that arecontagiousandepidemicin nature, are classified as infectious diseases.