One adaptation involves altering the shape of the eye. An elliptical eye produces the least amount of friction and pressure. Sharks, among the fastest swimming fishes, have highly elliptical eyes. Another adaptation is vertical eyelids - thin transparent tissue that cover the cornea, thus reducing not only friction on the eye but also eddies that form around the eyes when the fish is swimming. This material may be copied for use in student classroom projects and reports.
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