Figs. 766 to 770. — Static Accommodative Devices. 



N 



Fig. 766. — The eye of Anableps. 



Because of the pyriform shape of 

 the lens the upper pupil and lower 

 retina are positioned for aerial 

 vision (A), the lower pupil and upper 

 retina for aquatic vision (W) (c.f., 

 Fig. 385). 



Fig. 767. — The tubular eye of a deep- 

 sea fish. 



The main retina is used for near 

 vision with a myopic optical system 

 (N) ; the accessory retina for distance 

 vision with a hypermetropic optical 

 system (D). 



Figs. 768 and 769. — The ramp-retina. 

 Fig. 768.— The eye of the ray. Fig. 769. — The eye of the horse. 



In each case distance vision is subserved by rays striking the lower 

 (hypermetropic) part of the retina {D) ; near vision is subserved by rays 

 striking the upper (myopic) part of the retma (N). 



Fig. 770. — The eye of the fruit bat. 



Distance vision is subserved by retinal elements at the top of a papilla (D) ; 

 near vision by elements in the trough between two papillae (N) {c.f.. Fig. 581). 



