However, he or she may close one eye to compensate for the problem. In children, the reason for not seeing double is that the brain may ignore the image it receives from the squinting eye. This shutting down is known as Suppression. Generally, exotropia progresses in frequency and duration. As the disorder progresses, the eyes start to turn out when looking at close objects as well as those in the distance. If left untreated, the eye may turn out continually, causing a loss of binocular vision or stereopsis. In young children with any form of strabismus, the brain may learn to ignore the misaligned eyes image and see only the image from the best-seeing eye. This is called amblyopia, or lazy eye, and results in a loss of binocular vision, impairing depth perception. In adults who develop strabismus, double vision sometimes occurs because the brain has already been trained to receive images from both eyes and cannot ignore the image from the turned eye. Additionally in adults who have had exotropia since childhood, the brain may adapt to using a "blind-spot", whereby it receives images from both eyes, but no full image from the deviating eye, thus avoiding double vision, and in fact, increasing peripheral vision on the side of the deviating eye. According to a study published in the American Journal of Ophthalmology, over 90 percent of children with intermittent exotropia become nearsighted by the time they’re 20. Causes
The causes of exotropia are not fully understood.
Undescended testes are associated with reduced fertility, increased risk of testicular germ-cell tumors, and psychological problems when fully-grown. Undescended testes are also more susceptible to testicular torsion (and subsequent infarction) and inguinal hernias. Without intervention, an undescended testicle will usually descend during the first year of life, but to reduce these risks, undescended testes can be brought into the scrotum in infancy by a surgical procedure called an orchiopexy.Although cryptorchidism nearly always refers to congenital absence or maldescent, a testis observed in the scrotum in early infancy can occasionally "reascend" (move back up) into the inguinal canal. A testis that can readily move or be moved between the scrotum and canal is referred to as retractile. Cryptorchidism, hypospadias, testicular cancer, and poor semen quality make up the syndrome known as testicular dysgenesis syndrome. Signs and symptoms
Infertility
Many men who were born with undescended testes have reduced fertility, even after orchiopexy in infancy. The reduction with unilateral cryptorchidism is subtle, with a reported infertility rate of about 10%, compared with about 6% reported by the same study for the general population of adult men. The fertility reduction after orchiopexy for bilateral cryptorchidism is more marked, about 38%, or six times that of the general population. The basis for the universal recommendation for early surgery is research showing degeneration of spermatogenic tissue and reduced spermatogonia counts after the second year of life in undescended testes. The degree to which this is prevented or improved by early orchiopexy is still uncertain.