The extraocular muscles must turn each eye inward; the sphincter muscles must work to make the pupil smaller; and the ciliary muscles must contract to allow the lens to change to a shape that will produce a clearer image. Solution: Focus on a distant object to immediately feel your eyes relax.
Its upper body is blue, the belly is silver, and the fins are yellowish-gray. The common amberjack can reach five to six feet (1.5 to 1.8 m) in length and more than 100 pounds (45 kg) in weight. The average weight, however, is 10 to 15 pounds (4.5 to 6.8 kg).
Full Answer. The average size of a tuna fish depends upon the species of the tuna fish. An albacore tuna fish averages around 15 to 40 inches in length and has a weight of approximately 10 to 25 pounds. The Atlantic or northern bluefin tuna, one of the largest species, weighs around 550 pounds. Other species of tuna include the southern bluefin, bigeye, bonito, skipjack, tongol and yellowfin tuna.