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blur

 
lack of sharpness in an x-ray image, usually due to patient motion.

blur

(blur) indistinctness, clouding, or fogging.
spectacle blur  the indistinct vision with spectacles occurring after removal of contact lenses, especially non–gas-permeable lenses; it is believed to result from chronic corneal hypoxia and edema.

blur 

1. Degradation of an image formed by an optical system as a result of lack of focusing, aberrations, diffusion of light, etc.
2. A pattern in which the border is indistinct. See lens flare; blurred vision.
blur back test See plus 1.00 D blur test.
blur circle A circular patch of light formed on the retina resulting from a point object whose image is focused either in front of, or behind the retina, or due to excessive aberrations of the optical system of the eye. The size of the blur circle increases with the distance of the ocular image from the retina and with the diameter of the pupil. Its diameter can be expressed in angular terms (in min arc) as
α = 3.48 ✕ ΧFd
where ΧF is the defocus (in dioptres) with respect to the object point, and d the pupil diameter (in mm) (Figs. B4 and B5). Example: An object at infinity is viewed by a 2 D uncorrected myope with a 4.0 mm pupil diameter, i.e. α = 3.48 ✕ 2 ✕ 4 = 28 min arc. Syn. circle of confusion; circle of diffusion. See aberration; depth of field.
plus 1.00D blur test See plus 1.00 D blur test.
blur point See blur point.
spectacle blur Reduction in visual acuity noticed with spectacles after removal of hard contact lenses (PMMA). This may be due to corneal oedema, alteration of the corneal index of refraction, surface distortion of the cornea, etc. Refitting the patient with gas permeable lenses usually relieves this symptom.
Fig. B4 Blur circle corresponding to an image formed in front of the retinaenlarge picture
Fig. B4 Blur circle corresponding to an image formed in front of the retina
Fig. B5 Effect of pupil size on the blur circle. O9 is the image of object O formed by the optics of the eyeenlarge picture
Fig. B5 Effect of pupil size on the blur circle. O9 is the image of object O formed by the optics of the eye

blur

lack of clarity in the radiograph caused by movement of the x-ray tube, subject or film during exposure.

Patient discussion about blur

Q. My vision is blurry and I see zigzag lines, what is it from? Every now and again, usually after sitting a few hours in front of the computer or not sleeping enough at night, I start getting blurry vision. I see zigzag lines in front of my eyes and it can take sometimes an hour to go away. What is this from?

A. It sounds like you have a migraine. A migraine that comes with blurry vision and zigzags (an aura) is called a classic migraine. The aura of migraine typically lasts from 20 minutes to an hour. Some patients have prolonged aura symptoms that can last hours to days. The aura also typically ends before the headache itself begins. When migraine aura symptoms are prolonged or last into or through the headache phase these types of migraine are commonly referred to as complicated migraines.

Q. I have fibromyalgia and am having terrible vision problems...double, blurred, feel off blance.Is this common?

A. Blurry vision is not a usual symptom in fibromyalgia. If you are experiencing this on a permenant basis you should see a doctor- either a neurologist or an ophthalmologist to rule out other vision conditions that might be causing this.

Q. What are the sides effects of alcoholism beside dizziness and blur?

A. In the short term, excessive alcohol consumption may cause vomiting and metabolic disturbances, seizures and coma. In the long term, alcohol may damage the pancreas, liver and other organs, and expose to cancer of the mouth.

You may read more here:
www.nlm.nih.gov/medlineplus/alcoholism.html

More discussions about blur
References in periodicals archive ?
Voices seem to originate from farther back in the throat, words tend to be softer, blurrier, articulation is less crisp and exact.
In an era of corporate-packaged rock-n-roll, sex, and "shocking" art, the distinction between repression and rebellion (or "opening up" the culture versus reinforcing established power) is blurrier than ever.
The Old Rawlseans, as opposed to New Rawls, do not distinguish between comprehensive and political conceptions, and thus have a much blurrier notion of the difference between public and non-public reason.
In contrast, for a typical SEM, the majority of the secondary electrons that are used for imaging come from deeper and much less confined regions within the sample, creating blurrier images with less resolution than the ORION([R]) Helium-ion microscope.
This telescope has a much blurrier view than the Kitt Peak one, but has the advantage of covering a longer time period.
Blurrier global barriers and a constant rise in competition have made international recognition one of the best ways for a financial professional to compete in the international business arena.
We've all been there, excitedly rushing to the chemist's to pick up our photos only to find many of them are blurrier than a typical Valleys' television reception.
Certainly it still brings the likelihood of more wrinkles, blurrier vision, graying and thinning hair, saggier skin, more body fat, and less muscle power.
But the dividing line in Eugene may be blurrier than it used to be.
Fighter jets rush across the picture plane at sharp angles, some trailing vectors of smoke; a moving car freezes against an even faster, blurrier background; a racing speedboat is photographed by a camera positioned on the bow; a diver somersaults in two consecutive images.
French conductor Emmanuel Villaume's firm but unpushy baton work shapes and clarifies these blurrier musical colors, while Alan Burrett's diffuse lighting design acts as a softening agent on Michael Scott's gorgeously precise period sets and costumes.
The answers to these questions are by no means clear, and becoming blurrier all the time.