Use of stenopaeic slit are all except:-

*The Stenopic slit found in all the trial sets is 1-2 mm by 15-35 mm in size. It splits an opaque disc into two halves. *It has many uses in Ophthalmology. *Fincham test is used to differentiate that coloured halos are due to early cataract or acute congestive glaucoma related corneal decompensation. * A stenopic slit is passed across the pupil& halos are observed. If those are broken halos , cataract is the most common cause. If brightness is reduced but halos are intact, cornea is the common cause. *Stenopic slit is useful in finding out the axis of the cylinder. *Stenopic slit is used in cases of corneal opacities to find out the optimal site for optical iridectomy. After dilating the pupil with a mydriatic, the slit is rotated in front of the eye and the axis which gives maximum clarity is chosen for optical iridectomy. Ref: Parson's Diseases of the eye, 22nd/e p.204