Animal Eyes Book

1	The origin of vision	1
	The first eyes	1
	What is an eye?	4
	Why and from what did eyes evolve?	6
	The course and pace of eye evolution	7
	Did eyes evolve once or many times	10
2	Light and vision	16
	The nature of light	16
	Light intensity	19
	Contrast	24
	Wavelength and colour	24
	Polarization	29
3	What makes a good eye?	33
	Fundamentals	33
	Resolution	36
	Sensitivity	47
4	Aquatic eyes: the evolution of the lens	56
	Evolutionary origins	56
	The pin-hole eye of Nautilus	57
	Spherical lenses	59
	Lenses with refractive index gradients	60
	Eyes of fish and cephalopods	63
	Matching eye to environment	66
	Eyes with non-spherical lenses	69
5	Lens eyes on land	72
	A new optical surface	72
	Basic optics of cornea and lens	73
	Variations on the lens/cornea theme in land vertebrates	81
	Amphibious eyes	93
	Invertebrate eyes with corneal optics	94
6	Mirrors in animals	104
	Mirrors in eyes	104
	The physical optics of animal reflectors	114
	Uses of multilayer reflectors in structures other than eyes	118
7	Apposition compound eyes	125
	Origins	125
	A little history: apposition and neural superposition	127
	Basic optics	131
	Ecological variations in apposition design	142
8	Superposition eyes	156
	Introduction - the nature of superposition imagery	156
	Refracting superposition	159
	Superposition and afocal apposition	168
	Reflecting superposition	172
	Parabolic superposition	176
9	Movements of the eyes	178
	How humans acquire visual information	179
	Are other animals like us?	183
	Insect flight behaviours seen as eye movement	186
	Why not let eyes wander? Some consequences of image motion	187
	Exceptions: rotational scanning by one-dimensional retinae	193
	Principal symbols used in the text	201
	References	202
	Index	215