VISION. 





close atmosphere of the church. At the con- 

 clusion of the service, on rising from the 

 kneeling posture, he was alarmed at finding 

 that the crimson velvet cushion and hangings 

 of the pulpit appeared of a dark violet hue, 

 and that other familiar objects which he knew 

 to be red, had likewise changed to bluish 

 green ; there was at the same time some gid- 

 diness and discomfort in the head. Having 

 rested in the vestry about ten minutes, the 

 symptoms gradually passed away, the crimson 

 objects becoming less and less blue, and the 

 red objects gradually resuming their proper 

 colour. Aperient medicine, c., was pre- 

 scribed, and we are not aware of any other 

 attack having been experienced. 



Another case occurred during the great 

 Exhibition in Hyde Park. A stout plethoric 

 farmer, aged 52, visited London, and had 

 undergone much fatigue and excitement in 

 seeing the various objects of interest. On the 

 third day, alter spending some hours in the 

 exhibition, he felt giddy and oppressed, and 

 remarked that the crimson hangings appeared 

 of a dull brownish green. This led him to 

 notice other objects, and he ascertained that 

 he could no longer discern the difference be- 

 tween reds and greens generally, though yel- 

 lows and blues retained their proper colour. 

 On his 1,-aving the building, the uniform of 

 the footguards and the colour of the foliage 

 of the trees, nearly assimilated. When he 

 reached home, he slept for three hours ; and 

 on awaking, was much relieved at finding 

 that the power of discerning colours had re- 

 turned. 



The extraordinary variety and glare of co- 

 lours at the exhibition was singularly dis- 

 tressing to the eyes, and numerous persons 

 suffered from congestion of the choroid in 

 consequence. 



According to M. Cunier, temporary achro- 

 matopsy almost always constitutes one of the 

 symptoms of congestive amblyopia in per- 

 sons affected with hemorrhoids and venous 

 congestion of the abdomen. The confusion 

 between the sensations of red and blue, takes 

 place every time that the encephalo-ocular 

 turgescence is augmented by the effect of a 

 lively emotion, anger, a rapid walk, too great 

 application of the "eyes, &c.* That eminent 

 oculist relates the following case. He was 

 consulted by an officer of artillery, who suffered 

 in a slight degree from congestive amblyopia. 

 Every time that he performed manoeuvres, 

 and fatigue increased the cerebro-ocular con- 

 gestion, the men appeared dressed entirely 

 in blue ; the white waistbelts he distinguished, 

 but the red worsted epaulets, the red tuft of 

 the shako, the facings of the coat and red 

 stripes down the trowsers, appeared blue. 

 He could see that the shako and trowsers 

 were of black cloth. A brief repose, with 

 cold water to the eyes and forehead, soon re- 

 stored natural vision. 



An interesting example of temporary achro- 

 matopsy, doubtless the effect of congestion, 



Op. cit. p. 49. 



is related by Professor Wartmann. M Thury, 

 an ex-professor of botany in the academv of 

 Lausanne, had walked during the night from 

 Geneva to Nyon to witness a magnificent 

 aurora borealis, which shone on the night of 

 the 17th and 18th of November, 1848? To 

 his great surprise and disappointment, he 

 could not discern any difference between the 

 blue of the sky and the magnificent blood 

 colour of the aurora, which was viewed with 

 rapture by. all around. Singular to say, another 

 lady of Geneva, a septuagenarian, presented 

 precisely the same peculiarity, though both 

 she and the professor had distinctly seen 

 mam previous auroras. 



The following case, which occurred under 

 our own observation, is an example of tem- 

 porary achromatopsy caused by vitiated blood 

 circulating through the brain and retina, and 

 disturbing the functions of those organs : 



Mr. H., a solicitor aged 37, of a spare 

 make and melancholic temperament, is fre- 

 quently subject to attacks of congestion of 

 the liver followed by vomiting and purging of 

 bile. These attacks are ushered in by dull 

 pain in the head and tenderness of the eye- 

 balls, rendering motion of them distressing. 

 At such times he is quite incapable of dis- 

 tinguishing colours, all objects being simply 

 divided into two classes, black and white 

 with their intermediate shades of grey. The 

 vision of objects continues perfectly distinct, 

 but it is not until the portal system has been 

 relieved that the perception of colours is 

 recovered, and then yellow is the first dis- 

 tinguished. If however he takes five grains 

 of calomel, the attack is cut short and the 

 power of discriminating colours at once re- 

 stored. There is nothing whatever unusual 

 about his eyes, and under ordinary circum- 

 stances he possesses perfectly natural vision. 



Achromatopsy may be the result of injury, as 

 in the following casa related by Dr. Boys de 

 Loury.* An individual was struck by a pistol 

 ball which entered his mouth without touch- 

 ing the tongue and broke through the hard 

 palate and base of the orbit. After his re- 

 covery from the wound, the injured eye re- 

 tained but little sight ; only a small spot of 

 the retina was sensible to light, and to use 

 this, the eye was obliged to be thrown con- 

 siderably to one side. Then objects were 

 seen distinctly but without colour. This 

 person described a palette spread with co- 

 lours, as a plate with many holes, and con- 

 founded the thumb opening with the spots 

 where the colours were placed. 



Various explanations, differing widely, have 

 been offered to account for the insensibility 

 of the eyes to colour ; and we may re- 

 mark that the subjects of this affection have 

 in several instances been men of intellectual 

 eminence. As for example, the metaphy- 

 sician Dugald Stewart, Dr. Dalton the illus- 

 trious chemist, Mr. Troughton the eminent 

 optician, Dr. Sommers, Dr. Unzer, of Al- 

 tona, and Professor Brandis. The opinion 



* Revue M&licale, Xov. 1843. 

 5 A 2 



