The red-eared slider has an exceptional seven types of color-detecting cells in its eyes.
Fritsches, Kerstin A.; Warrant, Eric J. (2013). "Vision". In Wyneken, Jeanette (ed.). The Biology of Sea Turtles. CRC Press. pp. 31–58. ISBN 978-1-4398-7308-3. OCLC 828509848










