| Dictionary, Encyclopedia and Thesaurus - The Free Dictionary 3,908,183,210 visitors served. |
Dictionary/ thesaurus | Medical dictionary | Legal dictionary | Financial dictionary | Acronyms | Idioms | Encyclopedia | Wikipedia encyclopedia | ? |
focus |
Also found in: Dictionary/thesaurus, Legal, Encyclopedia | 0.01 sec. |
|
|
focus /fo·cus/ (fo´kus) pl. fo´ci [L.]
1. the point of convergence of light rays or sound waves. 2. the chief center of a morbid process.fo´cal epileptogenic focus the area of the cerebral cortex responsible for causing epileptic seizures. Ghon focus the principal parenchymal lesion of primary pulmonary tuberculosis in children.
focus [fō′kəs] Etymology: L, hearth 1 a specific location, as the site of an infection or the point at which an electrochemical impulse originates. 2 the point at which light rays converge after passing through a lens. focus [fo´kus] (pl. fo´ci) (L.) 1. the point of convergence of light rays or sound waves. 2. the chief center of a morbid process. Ghon focus the primary parenchymal lesion of primary pulmonary tuberculosis in children; when associated with a corresponding lymph node focus, it is known as the primary or Ghon complex. Called also Ghon tubercle. grid focus in radiology, a determination made by drawing an imaginary line from the outside of the width of the grid to where it intersects with a centering point. Called also grid radius.
focus pl. foci [L.] 1. the point of convergence of light rays, x-rays or sound waves. 2. the chief center of a morbid process. See also focal spot.
focus 1. The point at which rays of light converge after passing through a convex lens to form a real image (real focus), or diverge from (virtual focus) after passing through a concave lens. 2. The centre or starting point of a disease process. 3. To adjust an optical system (e.g. camera or projector) in order to obtain a sharp image. Plural: foci. Syn. focusing. See confocal; principal focus; focal line.
aplanatic foci A pair of conjugate object and image points for which an optical system is free of spherical aberration. Syn. aplanatic points. dark focus See resting state of accommodation. depth of focus See depth of focus. principal focus The axial image point produced by an optical system of an infinitely distant object (the second principal focus or posterior principal focus), or that axial object point for which the image will be formed at infinity (the first principal focus or anterior principal focus). A converging optical system or lens has two principal foci that are real. A diverging optical system or lens has a second principal focus that is virtual. In curved mirrors the two principal foci coincide. Depending upon whether the object is at infinity or at the principal focus, this same focal point becomes either the second principal focus or the first principal focus, respectively. Syn. focal point. See focal length; equivalent power; sign convention. real focus See focus. sagittal focus; tangential focus See oblique astigmatism. virtual focus See focus. focus A center, often of a disseminated disease–ie, cancer, infection Patient discussion about focus. Q. Is there a verity of exercises i can do with my child that would be helpful for him to be more focused and relaxed and by that help him to control the ADHD effects ? A. from our experience - any activity is a good activity...if he feels hyperactive during homework or studying, going out and running around the block will be enough for him. if he can't do that, doing push ups, situps, and even jumping in one place can help- although i must say it is irritating as hell... try practicing also breathing techniques in order to relax. Q. My mind is getting confused now and i am losing on my focus. why is this change happening in me? I am a bipolar for the past 1 year. With the help of the medicines my episodes has come down. My mood is good and stable. Even my friends say that I am well as compared to previous years. But since last week I am not able to sleep well. My disrupted and reduced sleep is making me stressed. I just get 2-3 hours of sleep at night. After my lunch my tiredness starts again. My mind is getting confused now and I am losing on my focus. Why is this change happening in me? A. There are some possibilities that you are not taking your diet in time or your diet may not be nutritious as per your requirements. This can cause you to have increased stress and you can lose your sleep. This may increase the tiredness. Check if you are taking your medicines in right time. This can also be due to your stress. You may have stress due to your lifestyle too, which needs to be well managed in a healthy way. You can meet your doctor, as any increase in stress due to sleep deprivation can raise the chances of episodes to return back. Read more or ask a question about focushttp://www.youtube.com/watch?v=YdO5m_mfaTQ&eurl=http://www.imedix.com/health_community/vYdO5m%5EmfaTQ_bipolar_disorder_facts?q=bipolar%20disorder&feature=player_embedded Want to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit the webmaster's page for free fun content. |
|
| Medical Dictionary |
| Free Tools: |
For surfers:
Free toolbar & extensions |
Word of the Day |
Help
For webmasters: Free content | Linking | Lookup box | Double-click lookup |
|---|