What Are Rods and Cones?

To understand how integral the retina is towards sight, think of the eye as the camera and the retina its film, or the memory card if you want to use a modern example. Within the retina are special cells called photoreceptors which consist of rods and cones.

The rods are the most sensitive of the photoreceptors, adjusting to changes in light, shape, and movement. Interestingly, they contain just a single type of light sensitive pigment and are therefore ineffective in producing the colors we see every day. And yet when we’re in a room with low light, the rods are essential in helping us maintain clear vision.

The cones are less sensitive to light than the rods, but unlike the rods, they are able to process colors. As light comes into the eyes, the cones process these signals to the brain which creates a perception of color. Hence, the cones are sort of responsible for painting the world around us in various hues, provided there is a sufficient amount of light. Colorblindness tends to result when an individual is “missing” a cone in their retina or one of them happens to be weaker than the rest.

Have you ever wondered why it’s momentarily difficult to see when entering a dark room such as a movie theater? Upon entering, the cones are doing their job, which means the rods are resting. After a few minutes, the rods begin to take over the responsibility of helping you see clearer.

This information is presented by Retina Macula Specialists of Miami, the largest private retina practice in the city. We are a nationally acclaimed retina practice dedicated to the medical and surgical management of vitreoretinal diseases. Each of our extensively trained doctors are Diplomates of the American Board of Ophthalmology and are highly qualified to treat a wide variety of retinal conditions including but not limited to diabetic retinopathy, retinal detachment, macular problems like macular hole treatment, age-related macular degeneration, and CSR. We have three convenient locations in Miami, Coral Gables, and North Miami Beach. For contact information or to request an appointment, please visit https://www.retinamaculamiami.com.