The cause of a coloured &;Halo&; in narrow angle glaucoma is
Clinical Features of Glaucoma - Cupping of disc. - Raised intraocular pressure with coloured halos due to corneal oedema Ref khurana 6th edition pg 1234 - Visual field defect.
Increase IOP
Corneal oedema
Lenticular changes
Lacrimation
Glaucoma