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Why can a pterygium interfere with vision when it grows across the cornea?
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eye disease
An ophthalmologist performing LASIK eye surgery.
A pterygium can interfere with vision through two primary mechanisms as it grows across the cornea:
- Obstruction: If the growth encroaches upon the center of the cornea, it may cover the pupil, physically blocking light from entering the eye.1
- Surface Distortion: As the membrane contracts, it alters the natural curvature of the corneal surface. This change in shape induces astigmatism, which results in blurred vision.1