Mild internal and external cryptopia in children does not cause eye discomfort, while high obliquity causes eye discomfort in vertical cryptopia, and rotational cryptopia causes obvious eye and general discomfort. The symptoms of cryptotropia are also related to general health and mental status. The following symptoms often occur in cryptorchidism: 1. Headache, eye pain and photophobia often occur after prolonged vision, which is caused by eye muscle fatigue due to the continuous use of neuromuscular reserves. 2. Blurred or overlapping or serial handwriting when reading, sometimes intermittent diplopia, intermittent strabismus, and even binocular visual disorder if viewed with one eye instead of feeling clear and effortless. 3. Poor stereoscopic perception, unable to accurately determine the position and distance of spatial objects. Cryptorchidism may also show neuro-radiological symptoms such as nausea, vomiting, insomnia, conjunctival and lid margin congestion, etc.