Ectopia lentis is a displacement or malposition of the eye's crystalline lens from its normal location. A paial dislocation of a lens is termed lens subluxation or subluxated lens; a complete dislocation of a lens is termed lens luxation or luxated lens. Uniocular diplopia is due to paial aphakia. Edge of subluxated lens is seen as dark crescent line on distant direct ophthalmoscopy. Shining bright golden crescent on slit-lamp examination. Phacodonesis may be seen. Ref: AK Khurana 6thE pg217