Blue visual field defects occur when the tissues in the eye that control the color blue become abnormal. Visual field defects are a common symptom of many neurological disorders, and damage to different parts of the visual pathway and different diseases can lead to different visual field defects. So, what are the causes of blue visual field defects? Here are some of the causes of blue visual field defects: Glaucomatous visual field defects cause blue visual field defects include many types, such as bow-shaped defects, nasal lateral step-like defects, and scalloped defects. The more severe the visual field damage, the greater the impact on quality of life, and the assessment of visual field damage is the most important predictor of disease progression and treatment. In optic nerve compression, there is no problem with the optic nerve itself, but rather vision loss and visual field defects occur due to tumor or aneurysm compression that irritates the optic nerve and optic cross. Damage to one side of the optic nerve, causing total blindness in that eye. Injury to the middle part of the optic cross, causing temporal partially blindness of the visual field in both eyes. Injury to the optic tract on one side, causing simultaneous partially blindness on one side of the visual field of both eyes. Primary optic neuritis, optic nerve glioma , less common. Injury to the optic tract, lateral geniculate body, optic radiation or visual center causes ipsilateral hemianopia in both eyes, i.e., nasal hemianopia in the affected visual field and temporal hemianopia in the contralateral visual field.