In the previous chapter we have spoken of an appearance commonly seen in successfully couched eyes--viz., an unusual distinctness of the large vessels of the choroid in the ophthalmoscopic picture. It is necessary to insist that in such cases the vessels are not sclerosed; they are seen with unusual distinctness simply because the pigment which usually hides them from view has disappeared. What is more, a careful study of a number of these cases has created a strong impression that the deficiency in pigmentation affects both the pigmentary layer of the retina and also the pigment of the choroid. The absence of the former lays bare what lies behind it; the absence of the latter is inferred from the general appearance of pseudo-albinism. These findings are the more noteworthy by reason of their contrast to the usual deep pigmentation of the Indian eye. Some of our specimens throw light on this phenomenon, for we observe in them two changes: (1) The pigmentary layer of the retina is irregularly thinned and altered, and at some points its pigment can be seen migrating into the choroid; (2) the choroidal pigment itself is extensively altered in an irregular manner, being heaped up in some areas and thinned in others. It is necessary to remember that, inasmuch as our specimens are wholly obtained from the coucher’s failures, whilst the interesting appearance we are discussing is best seen in his successes, we cannot expect very definite results from our pathological material, since the changes we desire to study are there overlaid and obscured by those of pathological processes, such as hypertony, hypotony, and inflammation. =Glaucoma.=