Cone cellCone cells, or cones, are photoreceptor cells in the retinas of vertebrates' eyes, including the human eye. They respond differently to light of different wavelengths, and the combination of their responses is responsible for color vision. Cones function best in relatively bright light, called the photopic region, as opposed to rod cells, which work better in dim light, or the scotopic region. Cone cells are densely packed in the fovea centralis, a 0.
Iris dilator muscleThe iris dilator muscle (pupil dilator muscle, pupillary dilator, radial muscle of iris, radiating fibers), is a smooth muscle of the eye, running radially in the iris and therefore fit as a dilator. The pupillary dilator consists of a spokelike arrangement of modified contractile cells called myoepithelial cells. These cells are stimulated by the sympathetic nervous system. When stimulated, the cells contract, widening the pupil and allowing more light to enter the eye.
HypersomniaHypersomnia is a neurological disorder of excessive time spent sleeping or excessive sleepiness. It can have many possible causes (such as seasonal affective disorder) and can cause distress and problems with functioning. In the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), hypersomnolence, of which there are several subtypes, appears under sleep-wake disorders. Hypersomnia is a pathological state characterized by a lack of alertness during the waking episodes of the day.
ChronobiologyChronobiology is a field of biology that examines timing processes, including periodic (cyclic) phenomena in living organisms, such as their adaptation to solar- and lunar-related rhythms. These cycles are known as biological rhythms. Chronobiology comes from the ancient Greek χρόνος (chrónos, meaning "time"), and biology, which pertains to the study, or science, of life.
PhenelzinePhenelzine, sold under the brand name Nardil, among others, is a non-selective and irreversible monoamine oxidase inhibitor (MAOI) of the hydrazine class which is primarily used as an antidepressant and anxiolytic. Along with tranylcypromine and isocarboxazid, phenelzine is one of the few non-selective and irreversible MAOIs still in widespread clinical use. It is typically available in 15 mg tablets and doses usually range from 45–90 mg per day. Synthesis of phenelzine was first described by Emil Votoček and Otakar Leminger in 1932.
Circadian rhythm sleep disorderCircadian rhythm sleep disorders (CRSD), also known as circadian rhythm sleep-wake disorders (CRSWD), are a family of sleep disorders which affect the timing of sleep. CRSDs arise from a persistent pattern of sleep/wake disturbances that can be caused either by dysfunction in one's biological clock system, or by misalignment between one's endogenous oscillator and externally imposed cues. As a result of this mismatch, those affected by circadian rhythm sleep disorders have a tendency to fall asleep at unconventional time points in the day.
Idiopathic hypersomniaIdiopathic hypersomnia (IH) is a neurological disorder which is characterized primarily by excessive sleep and excessive daytime sleepiness (EDS). The condition typically becomes evident in early adulthood and most patients diagnosed with IH will have had the disorder for many years prior to their diagnosis. , an FDA-approved medication exists for IH called Xywav, which is oral solution of calcium, magnesium, potassium, and sodium oxybates; in addition to several off-label treatments (primarily FDA-approved narcolepsy medications).
Optic neuritisOptic neuritis describes any condition that causes inflammation of the optic nerve; it may be associated with demyelinating diseases, or infectious or inflammatory processes. It is also known as optic papillitis (when the head of the optic nerve is involved), neuroretinitis (when there is a combined involvement of the optic disc and surrounding retina in the macular area) and retrobulbar neuritis (when the posterior part of the nerve is involved). Prelaminar optic neuritis describes involvement of the non-myelinated axons in the retina.
Free-running sleepFree-running sleep is a rare sleep pattern whereby the sleep schedule of a person shifts later every day. It occurs as the sleep disorder non-24-hour sleep–wake disorder or artificially as part of experiments used in the study of circadian and other rhythms in biology. Study subjects are shielded from all time cues, often by a constant light protocol, by a constant dark protocol or by the use of light/dark conditions to which the organism cannot entrain such as the ultrashort protocol of one hour dark and two hours light.
Near-sightednessNear-sightedness, also known as myopia and short-sightedness, is an eye disease where light focuses in front of, instead of on, the retina. As a result, distant objects appear blurry while close objects appear normal. Other symptoms may include headaches and eye strain. Severe near-sightedness is associated with an increased risk of retinal detachment, cataracts, and glaucoma. Myopia results from the length of the eyeball growing too long or less commonly the lens being too strong. It is a type of refractive error.
