Intro | Amacrine Cells | Back of the Eyeball | Bipolar Cells | Blind Spot & Optic Nerve | Cone Receptors | Retinal Ganglion Cells | Horizontal Cells | Rod Receptors
Part 1: Image-Mapped Tutorial
Part 2: Matching Self-Test
Part 3: Multiple-Choice Self-Test
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An enormous amount of information is integrated and compressed within the retinal circuits; over 130 million receptor cells converge on the approximately 1 million optic nerve fibers that form the optic nerve. The optic nerve exits the back of the eye through a hole called the optic disk. Since no receptor cells are located in this region, it forms a blind spot in the visual image of the external world. This blind spot is easily compensated for by the primary visual cortex with information obtained from the opposite eye. This automatic filling in of the blind spot with a visual percept is called completion.