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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 ?
The solution is remarkably simple--use the blurred image as initial estimation and, at each iteration step, determine the error an additional blurring with the known kernel would introduce.
The first court to adjudicate a dilution by blurring claim post-TDRA was the Fourth Circuit in a case involving the famous brand Louis Vuitton.
The open primary and the blurring of party distinctions with nebulous yet universally popular campaign themes could lead to many other unintended consequences that go far beyond, and are even more disturbing, than the mere blurring of ideological clarity.
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Since there's no end in sight - as the hollowing out of the corporate world continues with a passion - why not make blurring a corporate strategy?
Blurring the lines of pattern, Onsen, a timeless bamboo, incorporates Chado's subtle geometric.
Her recent juicily painted birds perched among hollyhocks, cymbidium orchids, and berries provided--despite the scenes' Audubon-like arrangements--vehicles for the painter's unconventional amplifications of scale, heightened colors, and deliberate blurring of focus and distortion of perspective.
Using a deformable telescope mirror controlled by computer, researchers can compensate for the blurring by generating an optical aberration exactly opposite that caused by the atmosphere.
Thanks to our Anti-Shaking, Face Tracking and De-Noise technologies now embedded into their devices, people can remove undesirable blurring and further enhance pictures right from the image source," Mr.
Along with blurring the image, Levin-stein's use of paint adds a patinaed look to what seems dully descriptive.
In response to the blurring caused by farsightedness, the eyes grew until images passing through them landed exactly on the retina.