Which cone type is typically the least numerous?

Which cone type is typically the least numerous?

• A. Long wavelength cones
• B. Short wavelength cones
• C. Medium wavelength cones
• D. All cone types are equally numerous

Answer: (B)

Short-wavelength cones are the least numerous. The retina has three cone types tuned to different parts of the spectrum—long (red), medium (green), and short (blue) wavelengths—but their numbers aren’t equal. The blue-tuned cones make up only a small fraction of all cones, while the red- and green-tuned cones are far more common. This imbalance means blue vision is supported by a relatively small cellular pool, which helps explain why blue color signals are less dominant and can be less precise in perception compared with red and green.

Short-wavelength cones are the least numerous. The retina has three cone types tuned to different parts of the spectrum—long (red), medium (green), and short (blue) wavelengths—but their numbers aren’t equal. The blue-tuned cones make up only a small fraction of all cones, while the red- and green-tuned cones are far more common. This imbalance means blue vision is supported by a relatively small cellular pool, which helps explain why blue color signals are less dominant and can be less precise in perception compared with red and green.