Trilobites are found worldwide and evolved rapidly, making them easily distinguishable from trilobites of other time periods
The answer is Convergence of images behind the Retina
Convex lens converges light to a principal focus. The thickness of the lens determines the focal length (distance between the center of the lens and the principal focal point). Therefore, by evaluating the thickness of the convex lens, farsightedness, (an eye defect of convergence of images behind the retina) can be corrected by enabling images in the eye to form behind the retina.
Energy is lost at each trophic level.
Various clinical signs are seen by individuals affected by the disease. A number of options are possible for controlling this disease-causing fungus, though none has proved to be feasible on a large scale. The disease has been proposed as a contributing factor to a global decline in amphibian populations that apparently has affected about 30% of the amphibian species of the world.<span>[3]</span>