Meaning of Dunham. Celtic name. In Celtic, the name Dunham means - Dark skinned fighter.. Other origins for the name Dunham include - Celtic, Irish.The name Dunham is most often used as a boy name or male name. Celtic Name Meaning - Dark skinned fighter. Origin - Celtic.
eyeball. 1  Photoreceptors are the cells in the retina that respond to light. Their distinguishing feature is the presence of large amounts of tightly packed membrane that contains the photopigment rhodopsin or a related molecule.
The retina has about 6 million cones and 120 million rods. Cones are cone shaped structures and are required for bright light (day light) vision. Rods are rod like structures and are required for dim light (twilight/ night) vision. Both rods and cones contain light sensitive pigments. Rod cells contain a purplish pigment known as visual purple or rhodopsin and it is formed from vitamin A.