MRCP UK EXAMINATIONS

Detailed explanation-1: -Rod and cone photoreceptors are specialized neurons that function in the initial step of vision. These light-sensitive cells lie at the back of the retina adjacent to the retinal pigment epithelium (RPE), a cell layer that is vital for the survival of photoreceptors.

Detailed explanation-2: -The choroidal vasculature provides oxygen and nutrients to the photoreceptors. The capillary system, the choriocapillaris, lies directly under the Bruch’s membrane, while intermediate and large blood vessels of the system lie posterior to the capillaries.

Detailed explanation-3: -The human retina has two types of photoreceptors to gather light namely rods and cones. While rods are responsible for vision at low light levels, cones are responsible for vision at higher light levels. The light levels where both are functional are known as mesopic.