cataract in the eye
瞕 centers on a specific eye condition: a cataract, which clouds the lens and causes blurred vision.
瞕 combines 目 (eye) with 章, which likely contributes the sound ショウ and may relate to a pattern or mark, suggesting an eye condition that creates a visible opacity.
The eye radical 目 beside 章 (which can suggest a pattern or mark) paints a picture of a cloudy pattern forming over the eye, like a cataract.
For ショウ, imagine a show where the main actor has a cataract and can't see the stage: show -> ショウ, and the eye 目 is clouded.