Which health condition significantly increases the risk of blindness?

Hyperglycemia, or high blood sugar, is a critical factor that can lead to serious eye complications, including diabetic retinopathy. This condition is particularly prevalent among individuals with diabetes, where prolonged high blood glucose levels can damage the blood vessels in the retina, leading to vision loss. If left untreated, diabetic retinopathy can progress and potentially result in blindness.

In contrast, while the other health conditions listed can have an impact on general health and well-being, they do not carry the same direct link to an increased risk of blindness as hyperglycemia does. Conditions like conjunctivitis primarily affect the surface of the eye, hypothyroidism can lead to various systemic symptoms but not specifically to blindness, and arthritis, while it can cause discomfort and mobility issues, is not directly associated with vision loss in the same manner as hyperglycemia. Thus, hyperglycemia stands out as a significant risk factor for blindness, particularly in the context of diabetes management.