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What is Coloured halo not seen in: and explain in detail?
Ans: d (Spring catarrh) Ref: AK Khurana, 4th ed, p. 463Coloured halos are not seen in spring catarrhColored halos are seen in:a. Acute congestive glaucoma- due to fluid in corneal epitheliumb. Early stages of cataract - due to water droplets in lensc. Mucopurulent conjunctivitis-- due to prismatic effect of mucus present on corneaDifferentiating colored halos by:1. On washing the eye, coloured halos in mucopurulent conjunctivitis are eliminated.2. Fincham test: On passing a stenopaeic slit across the pupil, glaucomatous halos remain intact, while a halo due to cataract is broken up into segments.