Читать книгу Essentials of Veterinary Ophthalmology - Kirk N. Gelatt - Страница 109

In vacuum, light travels at a constant speed (c) of approximately 3 × 10⁸ m/s. As it strikes denser media, light undergoes three changes: (i) its velocity is reduced; (ii) its wavelength shortens; and lastly (iii) it is bent (unless it struck the surface of the medium at a 90° angle).