Foggy vision makes the world look as though it is behind steamed-up glass. It commonly reflects moisture or swelling in the cornea or early lens opacity.
Mechanisms
Corneal oedema from endothelial dysfunction, raised intra‑ocular pressure, or contact lens overwear produces a foggy, halo‑filled image. Early cataract and severe dry eye with unstable tear film can create similar sensations.
- People may see rainbow halos around lights in corneal oedema
- Foggy vision that improves as the day goes on is typical in some corneal dystrophies
- Acute glaucoma presents with foggy vision, pain, and nausea, requiring emergency care
- Weather and humidity changes can exacerbate surface-related fogginess
Clinical Relevance
Determining whether fogginess is episodic or constant guides urgency. Eye pressure measurement, corneal examination, and lens assessment are key.
- Any sudden foggy vision with pain or systemic symptoms needs urgent review
- Long-term management may include drops, contact lens changes, or surgery
- Protecting the cornea from further insult is essential in endothelial disease
- Education about warning signs supports timely return if symptoms escalate
