1. 1. Armstrong WM: The eye in Selkurt EE (ed): Physiology fourth ed. Boston. L i ule. Brown "anâ Cô 197(5 p 12 i.
2. 2. Gilberl JG: Age changes in color matching. J Geróntol 1210-215 1957.
3. 3. Bender MB: The incidence and type of perceptual .deficif Dcies in ehr àged -in Fields WS (ed): Neurological and Sensory Disorders in the Elderly. New * York Stratfon Intercontinental" Medi. . Book'.Cofp 1975. p.23.- * >
4. 4. Masiah T: The effect of ageing otf colour vision in females. Age and Ageing 7flH-1 L5 . 1978: : i'
5. 5. Chapanis A: Relationships between age visual acuity .and color .vision. Humah*-Biol 22:1-33 1950./