The Recognition of Flashing Coloured Lights by Persons with Normal and Defective Colour Vision.

sudden onset, oed&ma of retinal tissues, equally sudden cessation on removal of the cause and complete restoration of vision. (2) Whenever chronic nephritis complicates pregnancy, the visual disturbances are due to renal retinitis. (3) This retinitis is associated with high blood-pressure which, together with the signs of retinitis, have a tendency to persist after delivery. (4) This form of retinitis forms a useful guide in differentiating chronic nephritis complicating pregnancy from pre-eclamptic toxaemia. (5) It should really belong to the group of cases having hypertension and chronic nephritis preceding pregnancy. (6) Apart from their differentiating value, lesions of the retina help us to estimate the damage done to the vascular tree. (7) In the presence of commencing retinitis, the ophthalmologist should not hesitate to advise interruption of pregnancy.