2. (a) Using table data presented in the text, calculate the focusing power Fmin of the crystalline lens in the case when eye is focused to view distant objects. (b) Knowing that focusing power of the cornea is Feornea = 42 D, calculate minimum focusing power of the eye. (c) Find what if the eye focal length in this case. Eye optical system 1. Optical power of the cornea: Fornea = F, + F = F- optical power of the cornea front surface, D; F - optical power of the cornea back surface, D; R, radius of curvature of the comea front surface, m; Clary fibers R. Vous humor Comea Lene - radius of curvature of the comea back surface, R, Fora m; n1 - ambient refraction index (for air n = 1 and for water n, = 1.33); n - cornea refraction index: n- aqueous humour refraction index. 2. Optical power of the erystalline lens: Ferystalline tens =F +F, = s-a E- optical power of the crystalline lens front surface, D; F, - optical power of the crystalline lens back surface, D; R - radius of curvature of the crystalline lens front surface, m; R, - radius of curvature of the crystalline lens back surface, m; n - aqueous humour refraction index; n, - crystalline lens refraction index; n; - vitreous humor Oplo nerve Agueous humor Rena Scera refraction index. Table - Parameters for the Eye Radius, mm Index of refraction Front Back R = 7.8 Ramar =10 Ramin =6 Aqueous humour and vitreous humor R, = 7.3 R4maz =6 Ramie =5.5 Cornea n, =1.38 n4 =1.4 Crystalline lens (Fmin) Crystalline lens (Fmar) =1.33 3. Optical power of eye: F= Farnaa + Feristalline lens 4. Lens equation: 1 1. 1 Cornea Lens S- lens focal length (m); F- lens optical power (D); p - distance from the object to the lens or object distance (m); g – distance from the image to the lens or image distance (m). 5. Height of image on the retina: h.9 Н Е H - height of image on the retina, m; h - height of object, m; q - image distance (for human eye on the average is equal to 1.5 cm), m; p - distance of the object to optical system of the eye, m. 6. Lens magnification: н H- image height (m); h - object height (m), p - object distance (m); g - image distance (m). 7. Law of refraction: nisine, = nzsinez