First, Congenital amblyopia.
Second, Amblyopia due to cerebral intoxication.
Third, Retrobulbar neuritis and toxic amblyopia.
Fourth, Amblyopia ex anopsia.
Fifth, Hysterical amblyopia.
The most frequent amblyopias among the soldiers are exanopsia. Aside from a few amblyopias caused by prolonged occlusion of the eyelids, ptosis, or blepharospasm, the most frequent are due to opacities, ametropia, and strabismus. The hysterical amblyopias are, as a rule, associated with blepharospasm due to intense photophobia, and are sometimes associated with constant lacrimation. Vision at a distance is poor. The patient succeeds in reading but shows an asthenopia of fatigue. The cornea and the conjunctiva are anesthetic, and sometimes the eyelids also,—the so-called anesthesia en lunettes. The pupils are large but react properly. The patient complains of many species of disorder; loss of the sense of the third proportion, micropsia, megalopsia, diplopia, erythropsia, diplopia in two colors, inverted image, hemierythropsia, rotatory amblyopia. There is concentrated limitation of visual fields, exaggerated by fatigue and by intense light; reduced in dim light or when the patient is provided with smoked glasses; enlarged upon the instillation of atropin or with convex glasses. As a rule, with unilateral amblyopia, the functional disorders start in binocular vision. Practically the most important diagnostic feature is the anesthesia, since this cannot be readily simulated. Sometimes corneal anesthesia is found in non-hysterical persons, who may perhaps be regarded as potential hysterics.
Retrobulbar neuritis (nitrophenol).
Case 434. (Sollier and Jousset, April, 1917.)
A soldier of the 54th Artillery entered hospital 45, November 4, 1916. He had had a slight paralysis of the left brachial plexus in 1913, following a shoulder dislocation, but the only relic of this when the war began was a deltoid paresis. He had been working from August 13, 1915, at the factory in Saint-Fons, and was as yellow as the majority of the workers there. He had never shown xanthopsia.