XX CONTENTS 



Pag. 

 CALCULATION OF THE SITUATION AND SIZE OF DIOPTEIO 



IMAGES 456 



REDUCED EYE 458 



RELATIONS OF THE VISUAL Axis 463 



Visual angle Apparent size Size of retinal image 

 Acuteness of vision Smallest perceptible image 

 Measurement of visual acuteness. 



ACCOMMODATION 469 



Schemer's experiment Dispersion circles Diameter 

 of circles ot dispersion Accommodation line. 



MECHANISM OF ACCOMMODATION 473 



Narrowing of pupil Relation of iris to lens Changes 



in the lens. 



MEASUREMENT OF ACCOMMODATION 479 



Far point Determination of far point Near point 



Determination of near point Range of accommodation. 



OPHTHALMOSCOPY 484 



Reflection from retina Influence of angle between light 

 and visual axis Influence of size of pupil Influence 

 of nearness to pupil Ophthalmoscope. 



DIRECT METHOD 490 



Emmetropia Ametropia ; qualitative determination 

 Measurement of myopia Measurement of hypermetro- 

 pia Measurement of astigmatism. 

 INDIRECT METHOD . 496 



VISION v 



VISION 499 



Mapping the blind spot Yellow spot Field of vision. 



COLOR BLINDNESS . 501 



Method of examination and diagnosis. 



