A Bass’s Sense Of Sight.

By: Leo Watson

A bass’s sense of sight is obviously a primary influence in its behavior. Without good eye sight, bass would have a very short life span. There have been extensive studies done to determine just how well a bass can see, whether they see in color or black and white, and whether they see better at night or during the day. Tackle companies, as well as biologists, and fisherman alike have an extreme interest in the answers to these questions.
Eye sight plays an important role in the daily activities of all predator fish. In most situations and conditions, sight is the dominant sense used in seeking and selecting food. The photo sensory cells in a bass’ retina consist of cones ( for color vision ) and rods ( for black, white and shades of gray vision ). The bass’ eyes can receive five times more light than the human eye. This allows them to distinguish shapes, sizes, movements and color patterns the human eye can’t! Bass do this under varying water clarity and light conditions! Bass do not have eyelids so they can not blink or close their eyes. What they do have is a black pigment ( not present in the human eye ) that shades the photosensitive cells of the retina, which allows them to see well in extremely bright conditions with no discomfort. This dispels the conception that bright lights hurt the bass’ eyes!!!  Even though they are supposed to have a fixed focus pupil, bass have the ability to adjust their eyes to varying light conditions. The lens of the eye moves back and forth to change the roundness of the eyeball itself. By doing so this influences the amount of light entering the eye. Even though bass can spend a great deal of time in the sun without discomfort, they will often use a shady spot for ambushing prey. In fact, a feeding bass will do just that ! The visual acuity of the bass increases approximately three fold when looking into bright areas from shady ones.  Forage moving about in the bright sunlight have trouble seeing bass in the shade, but the reverse is not  true. The smart and crafty bass positions itself to take advantage of its superior vision. The bass has an extremely wide field of vision, a full 180 degrees for each eye. This allows them binocular vision in front and slightly upwards due to the overlap of the 180 degrees of sight with each eye. The bass is most effective at striking its prey and lures in their binocular zone. The only blind areas for the bass exist from his side fins back and under its belly. Research has shown that a bass’ vision increases with age. A bass’ eyes will continue to grow throughout its life regardless of its body growth. This could very well be another reason that lunker size bass are so difficult to fool with artificial baits.  The bass’ eyes are equipped for both day and night time vision. During the daylight, the cones in the retina move forward and the rods move backwards. At night the movement is reversed and they use their rods for black and white vision.  Periods when light level changes, such as dusk and dawn are interesting times. A humans eyes adjust to the change quite a bit quicker than those of a bass. It only takes about 30 minutes for most humans eyes to adjust to these changes. The bass is far less fortunate. At dusk the rods in the bass’ eye move forward in the retina for after dark vision.  It takes almost two hours for the bass’ eyes to   fully adjust for night vision. At about two hours before first light, the change back to daylight mode begins. Contrary to what most during anglers have been taught, fishing maybe extremely slow during the first two hours of dark and the last two hours prior to daylight.  Color vision is very important to the life of a bass. Most bass rely on their color vision for feeding, self defense and for spawning signals. Tests have shown that bass have excellent color vision and can easily distinguish between closely related colors. According to research studies, they can also tell the difference between different shades of the same color. 
In closing this article, I hope I have shed some light on the bass’ sense of sight. Hopefully I have  dispelled some previous myths. This information should help all to better understand how the bass’ sight works. Make sure you keep checking back for other articles written by myself.  This is the first in a series of articles on the bass’ senses. Always remember to take a kid fishing. Today's children are our future.   
Good luck, Leo Watson, Pro Staff - Contact me with your questions or comments at leo.watson@bassonhook.com  Leo's Articles are also published at  http://www.bassonhook.com

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