Miosis: Pupillary constriction. This may result from congenital absence of the dilatator pupillary muscle, defective sympathetic innervation, or irritation of the CONJUNCTIVA or CORNEA.Pupil: The aperture in the iris through which light passes.Miotics: Agents causing contraction of the pupil of the eye. Some sources use the term miotics only for the parasympathomimetics but any drug used to induce miosis is included here.Horner Syndrome: A syndrome associated with defective sympathetic innervation to one side of the face, including the eye. Clinical features include MIOSIS; mild BLEPHAROPTOSIS; and hemifacial ANHIDROSIS (decreased sweating)(see HYPOHIDROSIS). Lesions of the BRAIN STEM; cervical SPINAL CORD; first thoracic nerve root; apex of the LUNG; CAROTID ARTERY; CAVERNOUS SINUS; and apex of the ORBIT may cause this condition. (From Miller et al., Clinical Neuro-Ophthalmology, 4th ed, pp500-11)Mydriatics: Agents that dilate the pupil. They may be either sympathomimetics or parasympatholytics.Sarin: An organophosphorus ester compound that produces potent and irreversible inhibition of cholinesterase. It is toxic to the nervous system and is a chemical warfare agent.Reflex, Pupillary: Constriction of the pupil in response to light stimulation of the retina. It refers also to any reflex involving the iris, with resultant alteration of the diameter of the pupil. (Cline et al., Dictionary of Visual Science, 4th ed)Iris: The most anterior portion of the uveal layer, separating the anterior chamber from the posterior. It consists of two layers - the stroma and the pigmented epithelium. Color of the iris depends on the amount of melanin in the stroma on reflection from the pigmented epithelium.Iris Diseases: Diseases, dysfunctions, or disorders of or located in the iris.Moxisylyte: An alpha-adrenergic blocking agent that is used in Raynaud's disease. It is also used locally in the eye to reverse the mydriasis caused by phenylephrine and other sympathomimetic agents. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1312)Pilocarpine: A slowly hydrolyzed muscarinic agonist with no nicotinic effects. Pilocarpine is used as a miotic and in the treatment of glaucoma.Aqueous Humor: The clear, watery fluid which fills the anterior and posterior chambers of the eye. It has a refractive index lower than the crystalline lens, which it surrounds, and is involved in the metabolism of the cornea and the crystalline lens. (Cline et al., Dictionary of Visual Science, 4th ed, p319)Intraocular Pressure: The pressure of the fluids in the eye.Administration, Topical: The application of drug preparations to the surfaces of the body, especially the skin (ADMINISTRATION, CUTANEOUS) or mucous membranes. This method of treatment is used to avoid systemic side effects when high doses are required at a localized area or as an alternative systemic administration route, to avoid hepatic processing for example.Poisoning: A condition or physical state produced by the ingestion, injection, inhalation of or exposure to a deleterious agent.Ophthalmic Solutions: Sterile solutions that are intended for instillation into the eye. It does not include solutions for cleaning eyeglasses or CONTACT LENS SOLUTIONS.Cataract Extraction: The removal of a cataractous CRYSTALLINE LENS from the eye.Dictionaries, MedicalDictionaries as Topic: Lists of words, usually in alphabetical order, giving information about form, pronunciation, etymology, grammar, and meaning.Spastic Paraplegia, Hereditary: A group of inherited diseases that share similar phenotypes but are genetically diverse. Different genetic loci for autosomal recessive, autosomal dominant, and x-linked forms of hereditary spastic paraplegia have been identified. Clinically, patients present with slowly progressive distal limb weakness and lower extremity spasticity. Peripheral sensory neurons may be affected in the later stages of the disease. (J Neurol Neurosurg Psychiatry 1998 Jan;64(1):61-6; Curr Opin Neurol 1997 Aug;10(4):313-8)Paraparesis, Spastic: Mild or moderate loss of motor function accompanied by spasticity in the lower extremities. This condition is a manifestation of CENTRAL NERVOUS SYSTEM DISEASES that cause injury to the motor cortex or descending motor pathways.Lacrimal Apparatus Diseases: Diseases of the lacrimal apparatus.Lacrimal Duct Obstruction: Interference with the secretion of tears by the lacrimal glands. Obstruction of the LACRIMAL SAC or NASOLACRIMAL DUCT causing acute or chronic inflammation of the lacrimal sac (DACRYOCYSTITIS). It is caused also in infants by failure of the nasolacrimal duct to open into the inferior meatus and occurs about the third week of life. In adults occlusion may occur spontaneously or after injury or nasal disease. (Newell, Ophthalmology: Principles and Concepts, 7th ed, p250)Dacryocystorhinostomy: Surgical fistulization of the LACRIMAL SAC for external drainage of an obstructed nasolacrimal duct.Nasolacrimal Duct: A tubular duct that conveys TEARS from the LACRIMAL GLAND to the nose.Intubation: Introduction of a tube into a hollow organ to restore or maintain patency if obstructed. It is differentiated from CATHETERIZATION in that the insertion of a catheter is usually performed for the introducing or withdrawing of fluids from the body.Lacrimal Apparatus: The tear-forming and tear-conducting system which includes the lacrimal glands, eyelid margins, conjunctival sac, and the tear drainage system.Dacryocystitis: Inflammation of the lacrimal sac. (Dorland, 27th ed)Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)EncyclopediasEye: The organ of sight constituting a pair of globular organs made up of a three-layered roughly spherical structure specialized for receiving and responding to light.Molecular Sequence Annotation: The addition of descriptive information about the function or structure of a molecular sequence to its MOLECULAR SEQUENCE DATA record.Databases, Genetic: Databases devoted to knowledge about specific genes and gene products.Trigeminal Nerve: The 5th and largest cranial nerve. The trigeminal nerve is a mixed motor and sensory nerve. The larger sensory part forms the ophthalmic, mandibular, and maxillary nerves which carry afferents sensitive to external or internal stimuli from the skin, muscles, and joints of the face and mouth and from the teeth. Most of these fibers originate from cells of the TRIGEMINAL GANGLION and project to the TRIGEMINAL NUCLEUS of the brain stem. The smaller motor part arises from the brain stem trigeminal motor nucleus and innervates the muscles of mastication.Trigeminal Nerve Diseases: Diseases of the trigeminal nerve or its nuclei, which are located in the pons and medulla. The nerve is composed of three divisions: ophthalmic, maxillary, and mandibular, which provide sensory innervation to structures of the face, sinuses, and portions of the cranial vault. The mandibular nerve also innervates muscles of mastication. Clinical features include loss of facial and intra-oral sensation and weakness of jaw closure. Common conditions affecting the nerve include brain stem ischemia, INFRATENTORIAL NEOPLASMS, and TRIGEMINAL NEURALGIA.Trigeminal Nerve Injuries: Traumatic injuries to the TRIGEMINAL NERVE. It may result in extreme pain, abnormal sensation in the areas the nerve innervates on face, jaw, gums and tongue and can cause difficulties with speech and chewing. It is sometimes associated with various dental treatments.Trigeminal Neuralgia: A syndrome characterized by recurrent episodes of excruciating pain lasting several seconds or longer in the sensory distribution of the TRIGEMINAL NERVE. Pain may be initiated by stimulation of trigger points on the face, lips, or gums or by movement of facial muscles or chewing. Associated conditions include MULTIPLE SCLEROSIS, vascular anomalies, ANEURYSMS, and neoplasms. (Adams et al., Principles of Neurology, 6th ed, p187)Deep Brain Stimulation: Therapy for MOVEMENT DISORDERS, especially PARKINSON DISEASE, that applies electricity via stereotactic implantation of ELECTRODES in specific areas of the BRAIN such as the THALAMUS. The electrodes are attached to a neurostimulator placed subcutaneously.Cranial Nerve Neoplasms: Benign and malignant neoplasms that arise from one or more of the twelve cranial nerves.Electric Stimulation: Use of electric potential or currents to elicit biological responses.Phosgene: A highly toxic gas that has been used as a chemical warfare agent. It is an insidious poison as it is not irritating immediately, even when fatal concentrations are inhaled. (From The Merck Index, 11th ed, p7304)World War I: Global conflict primarily fought on European continent, that occurred between 1914 and 1918.Chemical Warfare Agents: Chemicals that are used to cause the disturbance, disease, or death of humans during WARFARE.Chlorofluorocarbons, Methane: A group of methane-based halogenated hydrocarbons containing one or more fluorine and chlorine atoms.Toxic Actions: A broad category of chemical actions with harmful or deadly effect on living organisms.Transition Temperature: The temperature at which a substance changes from one state or conformation of matter to another.Chemical Warfare: Tactical warfare using incendiary mixtures, smokes, or irritant, burning, or asphyxiating gases.Tension-Type Headache: A common primary headache disorder, characterized by a dull, non-pulsatile, diffuse, band-like (or vice-like) PAIN of mild to moderate intensity in the HEAD; SCALP; or NECK. The subtypes are classified by frequency and severity of symptoms. There is no clear cause even though it has been associated with MUSCLE CONTRACTION and stress. (International Classification of Headache Disorders, 2nd ed. Cephalalgia 2004: suppl 1)Headache Disorders: Various conditions with the symptom of HEADACHE. Headache disorders are classified into major groups, such as PRIMARY HEADACHE DISORDERS (based on characteristics of their headache symptoms) and SECONDARY HEADACHE DISORDERS (based on their etiologies). (International Classification of Headache Disorders, 2nd ed. Cephalalgia 2004: suppl 1)Migraine Disorders: A class of disabling primary headache disorders, characterized by recurrent unilateral pulsatile headaches. The two major subtypes are common migraine (without aura) and classic migraine (with aura or neurological symptoms). (International Classification of Headache Disorders, 2nd ed. Cephalalgia 2004: suppl 1)Amitriptyline: Tricyclic antidepressant with anticholinergic and sedative properties. It appears to prevent the re-uptake of norepinephrine and serotonin at nerve terminals, thus potentiating the action of these neurotransmitters. Amitriptyline also appears to antagonize cholinergic and alpha-1 adrenergic responses to bioactive amines.Headache: The symptom of PAIN in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of HEADACHE DISORDERS.Antidepressive Agents, Tricyclic: Substances that contain a fused three-ring moiety and are used in the treatment of depression. These drugs block the uptake of norepinephrine and serotonin into axon terminals and may block some subtypes of serotonin, adrenergic, and histamine receptors. However the mechanism of their antidepressant effects is not clear because the therapeutic effects usually take weeks to develop and may reflect compensatory changes in the central nervous system.Relaxation Therapy: Treatment to improve one's health condition by using techniques that can reduce PHYSIOLOGICAL STRESS; PSYCHOLOGICAL STRESS; or both.