Article first published: June 2022
Blurred or out-of-focus vision is in most cases due to a refractive error such as nearsightedness or astigmatism. Both can be corrected by glasses or contact lenses. But it can also be a sign of disease. We explain here how to distinguish symptoms of disease from defective vision – and what everyone can do to see better again.
It's important to begin by clarifying what blurred vision is. Affected people usually describe it as a loss of contrast or limited resolution in vision. Objects can appear foggy and out of focus at different distances. Some people have blurred vision in only one eye – failing to notice it until they cover their "good" eye.
If blurred vision occurs very suddenly and with dizziness or nausea, those affected should consult a doctor immediately. Because these symptoms can indicate a serious disease with repercussions beyond the eye alone.
Blurred vision can also be a sign of undetected diabetes or indicate damage to the blood vessels in the eye in existing cases of diabetes. Similarly, inflammation in the eye or low blood pressure can also affect vision. In all cases, a visit to the doctor is advisable to clarify the cause of these forms of blurred vision.
If vision becomes increasingly cloudy over time, this may be a symptom of a cataract (clouding of the lens) – and should also be checked by a specialist. For treatment, the clouded lens of the eye is surgically replaced with an artificial lens.