The Royal Albatross

       Imagine if your vision was so good that you clearly see an ant crawling on the ground from the top of a ten-story building. If you could, then you would have the vision of a Royal Albatross. The Royal Albatross, like most birds of prey, can see four-five times farther and clearer than the average human. This is due to the structure of its eye. Birds of prey have huge eyes when compared to that of a human’s. When the eye is larger the image on the retina is projected larger as well. Basically, the larger the eye the better the vision. Also, the larger eye has a bigger visual field. The visual field of the bird is 340˚ whereas a humans’ is 180˚. One of the only setbacks about having birds’ vision is the 60˚ blind spot above the head. The visual fields size has an effect on the refractive power of the eye. Since the visual field of the human eye is smaller the accuracy of the light hitting the fovea from a far is not as much. The cornea also plays a role in adjusting the light hitting the fovea.

 

       The Royal Albatross’s cornea is relatively flat compared to the mammalian eye giving it an optical or refractive power closer to zero. Our human eye on the other hand has a bulged cornea so the light bends on its way to the fovea. The flat cornea helps the Albatross see on or below the surface of the water. Another reson the Albatross has better vision is because it has two foveae. With two foveae the chance of light reflecting off an object and hitting one of them is higher. When light hits the fovea the clarity of the image is much more detailed. This because that area is densely packed with photoreceptors called cones which help you see bright colors making the vision better. The binocular field of this spectacular creature is long and narrow; therefore its engrossment on its prey is high. Since the field of vision is long, light can enter the eye from a distance. The narrowness of the visual field keeps the light focused on the fovea. If the light is usually hitting the fovea the visual acuity or the accuracy of its vision will be high.

       

       The visual acuity of this avian eye is way more than that of the mammalian eye. This is due to lifestyle adaptations. Visual acuity is very important when catching prey. The position of the eye of these birds overlaps their binocular vision. This helps them accurately determine the distance of itself from the prey. The binocular vision is not the only thing that helps them judge distance, though. Yellow or red oil droplets in the color receptors of their eye helps them judge distance and sharpens their vision. Another asset which comes from the eye for this bird of prey is the fact that it makes both, nocturnal and diurnal. This means they can see at night and in the morning. For aquatic birds, like the Royal Albatross, have a nictitating membrane which helps them see under water. With all its benefits, the better eye would be the avian eye.

 

Works Cited

 

"Bird Vision." Wikipedia. Wikimedia Foundation, n.d. Web. 11 Apr. 2015. <http://en.wikipedia.org/wiki/Bird_vision>.