Outer nuclear layer

Outer Nuclear Layer

The Outer Nuclear Layer (ONL) is a layer of the retina in the eye that contains the cell bodies of photoreceptor cells. These cells are responsible for converting light into electrical signals that the brain can interpret as visual images. The ONL is one of the ten layers of the retina, located between the Outer Plexiform Layer and the Photoreceptor Layer.

File:Retina layers.png

Diagram of the layers of the human retina. The Outer Nuclear Layer is labeled at right.

Structure

The Outer Nuclear Layer is composed primarily of the cell bodies of the two types of photoreceptor cells: rods and cones. These cells are densely packed in this layer, with the rods outnumbering the cones by approximately 20 to 1. The ONL is one of the thickest layers of the retina, reflecting the high density of photoreceptor cells it contains.

Function

The primary function of the Outer Nuclear Layer is to house the cell bodies of the photoreceptor cells. These cells are responsible for the initial conversion of light into electrical signals. The rods are responsible for vision in low light conditions, while the cones are responsible for color vision and detail perception in brighter light.

Clinical significance

Damage or disease affecting the Outer Nuclear Layer can lead to significant vision loss. Conditions such as Retinitis Pigmentosa and Age-related Macular Degeneration (AMD) can cause degeneration of the photoreceptor cells in the ONL, leading to progressive vision loss.

See also

• Retina
• Photoreceptor cell
• Retinitis Pigmentosa
• Age-related Macular Degeneration