Cones work in bright light and register detail ... One consequence of having extremely light sensitive eyes, is that they must be adequately protected during the day. Some animals accomplish ...

change size to regulate the amount of light entering the eye. Pupils are large in the dark to let more light in and small in bright light. Usually, the pupils in each eye dilate or constrict ...

with long hours of bright light in the summer and almost total darkness in winter. One theory is that in the winter, pressure inside the animal's eye builds due to the effort of keeping the pupils ...