The retina’s layers are inverted relative to the direction of incoming light. True or false?

The retina’s layers are inverted relative to the direction of incoming light. True or false?

• A. False
• B. Sometimes
• C. Not sure
• D. True

Answer: (D)

Light must travel through several retinal layers before it reaches the light-detecting cells. In vertebrate eyes, the photoreceptors sit next to the pigmented layer close to the choroid, so they are effectively behind other neural layers from the direction of incoming light. As a result, the retina is described as inverted relative to the light path—the light passes through ganglion, bipolar, and other cells before hitting the photoreceptors. A helpful nuance is that in the fovea, inner retinal layers are thinned to minimize obstruction and improve acuity, but the basic arrangement of photoreceptors being behind those layers remains. Therefore, the statement is true.

Light must travel through several retinal layers before it reaches the light-detecting cells. In vertebrate eyes, the photoreceptors sit next to the pigmented layer close to the choroid, so they are effectively behind other neural layers from the direction of incoming light. As a result, the retina is described as inverted relative to the light path—the light passes through ganglion, bipolar, and other cells before hitting the photoreceptors. A helpful nuance is that in the fovea, inner retinal layers are thinned to minimize obstruction and improve acuity, but the basic arrangement of photoreceptors being behind those layers remains. Therefore, the statement is true.