People with crossed eyes (strabismus) cannot see straight. Strabismus is caused by lesion of either of cranial nerves including oculomotor, trochlear and abducens. The lesion causes the lack of innervation to eye muscles and a change of eye position. For people with strabismus, when they look at an object, one of their eyes concentrates on the object while the other on a convergence angle that is less than zero. But after the treatment of glasses, vision therapy and surgery, they can see straight. In some cases, people learn to control their eyes to focus on one object and see straight.
When watching an object, the images of the object on the retinas of both eyes overlap with each other in the central pivot of brain and become a complete and sole image with three dimension, which is called the binocular single vision. But crossed eyes can not both focus on the same object, i.e., when one eye watches an object, the other cannot look at the same object because it inclines to the inner side. People with crossed eyes can only see things without three dimension, and they cannot distinguish whether the object is near or far away, which will of course many troubles in life, for example, they cannot thread a needle when doing sewing work, they cannot put things into a certain hole, they cannot fetch a small object nearby, and so on. Crossed eyes can influence people's daily life and study and work, so people with crossed eyes should go to doctor's as soon as possible for treatment, and it takes patience and perseverment.
People with crossed eyes can not see things straight. However, if they wear the special kind of eyeglasses, they will focus things and see things straight. They could go to the online stores to buy the special glasses to help them with the right vision. The online price will be suitable which will help them save a lot.