Turtle Eye Muscle Adapts To Deal With Obstructed Vision

Of the six muscles that move each eye, the muscles that move lateral eyes differ from the muscles of animals that move eyes viewing forward. In an earlier study, Ariel and his research team made an unexpected observation that a nerve that moves one of the pond turtle’s eye muscles, the superior oblique muscle, was active when that turtle moved its head from side to side, much like that of animals whose eyes view forward . In the current study, Ariel and the research team tested his theory that the pond turtle had characteristics of a front-eyed animal in three ways: physiologically, looking at the eye movement response to nerve stimulation; anatomically, examining how muscles were attached to the eyes and head; and behaviorally, examining eye positions. And, indeed, the researchers found that a turtle pulls its eyes in different directions when its head is out of its shell compared to when its head is retracted deep within its shell.
For the original version including any supplementary images or video, visit http://www.sciencedaily.com/releases/2013/09/130919121858.htm

Eye health and vision screening guidelines for adults and children: when should eyes be examined?

Follow up exam frequency will depend on the findings of your initial exam. If your eyes are found to be healthy at the initial exam, follow up exam frequency is typically once a year Pupillary dilation and eye pressure check are important components of yearly exam to evaluate the health of your retina, optic nerve, and to detect early glaucoma. If you dont have any eye symptoms and you had LASIK or PRK to correct nearsightedness, farsightedness, and/or astigmatism, you should continue yearly examinations with your eye doctor. Laser vision correction changes the shape of your cornea. The shape of your eye, however, remains the same. Therefore, you should have a dilated eye exam once a year to continue monitoring the health of your retina and optic nerve. Eye pressure needs to be checked once a year as well to continue monitoring for glaucoma.
For the original version including any supplementary images or video, visit http://www.examiner.com/article/eye-health-and-vision-screening-guidelines-for-adults-and-children-when-should-eyes-be-examined