Assessment of Homonymous Visual Loss and Its Impact on Visual Exploration, Activities of Daily Living (ADL) and Quality of Life (QoL)

Inclusion Criteria: \- Patients with homonymous visual field defects Primary inclusion criterion: (Stable) homonymous visual field defects, as obtained by binocular semi-automated kinetic perimetry (SKP), using the III4e stimulus, within on onset of at least six months ago, due to a vascular or a traumatic lesion. Further inclusion criteria: (i) general: physical, intellectual and linguistic abilities, necessary to understand the test requirements: no mobility limitations / hemiparesis, Minimental Status Examination Test score above 24, adequate knowledge of the German language, willingness to comply with the protocol, \> 18 years, informed consent. (ii) Ophthalmological: spherical ametropia max. ± 8 dpt, cylindrical ametropia max. ± 3 dpt, best corrected distant visual acuity \> 6/12 (= 0.5), isocoria, pupil diameter \> 3 mm, intraocular pressure ≤ 21 mmHg, normal anterior segments, no clinically relevant media opacities, normal appearance of the optic disc (cup to disc ratio = CDR ≤ 0.5, intraocular difference of CDR \< 0.3). \- Normal subjects (i) General inclusion criteria: Physical, intellectual and linguistic abilities needed to understand the test requirements: no mobility limimtaions / hemiparesis, Minimental Status Examination Test score above 24, adequate knowledge of the German language, willingness to comply with the protocol, \> 18 years, informed consent. (ii) Ophthalmological inclusion criteria: maximum allowed spherical ametropia at distance is ± 6.00 diopters and the maximum cylindrical ametropia is ± 2 diopters. The best corrected distance visual acuities are equal to, or better than 20/20 and 1.0, respectively, for those aged up to 60 years; better than 20/25 and 0.8 for those aged between 60 and 70 years; and better than, or equal to, 20/33 and 0.6 for those aged more than 70 years. All participants manifest equal pupil size, pupil diameter \> 3 mm, no relative afferent pupillary defect, intraocular pressure ≤ 21 mmHg, normal anterior segments, no clinically relevant media opacities, normal appearance of the optic disc (cup to disc ratio = CDR ≤ 0.5, intraocular difference of CDR \< 0.3) and normal central and peripheral fundus findings on direct and indirect undilated ophthalmoscopic examination. Exclusion Criteria: \- Patients with homonymous visual field defects: (i) General exclusion criteria: Pregnancy, nursing, asthma, HIV+ or AIDS, history of epilepsy or significant psychiatric disease, history of drug and alcohol abuse, Minimental Status Examination Test score below 24, medications known to affect visual field sensitivity. (ii) Ophthalmological exclusion criteria: diabetic retinopathy, infections (e.g. keratitis, conjunctivitis, uveitis), severe dry eyes, miotic drug, amblyopia, squint, nystagmus, albinism, any ocular pathology, in either eye, that may interfere with the ability to obtain visual fields, disc imaging or accurate IOP readings, keratoconus, intraocular surgery (except for uncomplicated cataract surgery) performed \< 3 month prior to screening, protanopia, deuteranopia, history or presence of macular disease and / or macular edema, ocular trauma. \- Normal subjects: (i) General exclusion criteria: pregnancy, nursing, mental or neurological diseases, Minimental Status Examination Test score below 24, history of coronary heart disease, stroke, diabetes mellitus, migraine, vasospasm/ Raynaud's disease, drugs indicating severe systemic diseases (e.g. anti-diabetic or anti-hypertensive medication for subjects under 70 years of age), drugs or medications influencing reaction time, history of drug and alcohol abuse, suspected lack of compliance. Subjects over 70 years of age will not be excluded for use of anti-hypertensive medication. (ii) Ophthalmological exclusion criteria: Amblyopia, strabismus, ocular motility disorders, retinal pathology, glaucoma, suspicion of glaucoma, ocular hypertension or any other sign of other optic neuropathy, macular degeneration, protanopia, deuteranopia, eye surgery (except for uncomplicated cataract surgery), any type of refractive surgery, history or signs of neuro-ophthalmological diseases, acute infections, diabetic retinopathy, use of miotic drugs.