Which symptom requires prompt attention?

Sudden loss of vision is a symptom that absolutely requires prompt attention because it can indicate serious medical conditions, such as retinal detachment, stroke, or other acute ocular or neurological issues. When vision loss occurs suddenly, it is crucial to seek immediate medical evaluation to determine the cause and to initiate necessary treatment promptly. Prompt intervention can be vital in preserving vision and preventing permanent damage.

In contrast, while diplopia (double vision) and pain in the eye can also signify underlying issues that may need evaluation, they do not pose the same immediate risk to vision as sudden loss of vision does. A gritty feeling in the eye typically suggests mild irritation or dryness, which may be less urgent and can often be managed with over-the-counter treatments. Therefore, sudden loss of vision stands out as the most critical symptom that warrants immediate medical attention.