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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 ?
In response to the blurring caused by farsightedness, the eyes grew until images passing through them landed exactly on the retina.
The market is also experiencing "channel blurring," which makes it possible to purchase seasonal chocolate (and indeed chocolate for any occasion) through myriad channels from the highest quality chocolatier to the dollar store.
Prior research has found that comparable blurring of picture blocks boosts their recognizability as parts of a single object.
A recent study by Eastbridge Consulting Group on worksite product trends confirms this continued blurring between the lines.
Traditionally, astronomers have eliminated some of this blurring in visible-light images by using speckle interferometry, which creates an image composed of many short exposures.
The blurring usually attributed to turbulence in the atmosphere is more often the result of telescope oscillations, tracking errors and flawed mirrors, McKechnie contends.
At the same time, the distinctions between some generics companies and traditional, R&D-led pharmaceutical companies are blurring as generics companies move up-stream and invest in R&D while pharmaceutical companies such as Novartis, Sanofi and Merck retain successful generic subsidiaries.
On the old imagery, we are working with the new Version 2 matte design tool, XBLUR, geometrics and color correction to lift foreground elements off of their backgrounds and give them a sense of depth through slight differential scaling of the layers, blurring and darkening of the background, and brightening of the foreground.
PMD is the blurring of an optical signal in high-speed networks caused by fiber imperfections or other stresses on optical fiber.
Besides adjusting the size and color palette, over 20 filters may be used to apply such effects as embossing, softening, sharpening, and blurring.
Insight: blurring digital-physical lines poses technology challenges for insurers.
We have been deceived into accepting what is currently the Trademark Dilution Revision Act of 2006 (hereinafter "TDRA"), and its multifactor test to measure trademark dilution by blurring, as the equitable and sensible anti-dilution law to police dilution of trademarks by blurring in the United States.