Visual Perceptual Learning Based Digital Therapeutics for Visual Field Defect After Stroke

Inclusion Criteria: * 19 years and older * At least 3 months after brain disease related to visual field defect * Verified brain disease in visual pathway related to occipital lobe, parietal lobe, temporal lobe or etc. using CT or MRI * Brain disease induced visual field defect * Able to use the VR(Virtual Reality) device * Able to use the app with a smart phone * Patient/legally authorized representative has signed the informed consent form Exclusion Criteria: * Complete hemianopsia * Epilepsy, photosensitivity, Parkinson's disease * Bilateral visual field defect * Hemispatial neglect * Ophthalmologic disorder that may interfere the trial. (Ptosis of Eyelid, Corneal Opacity, Diabetic Retinopathy, Glaucoma, Macular Degeneration etc.) * Inability to discontinue psychostimulants such as methylphenidate, modafinil, and amphetamine. * Candidate for carotid endarterectomy or stenting * Received ophthalmologic surgery or laser surgery within 3 months, except for the cataract surgery * Pregnant or breast feeding * Participating in other clinical trial * Any other condition that, in the opinion of the investigator, precludes participation in the trial