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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 classic literature ?
The other, a mere blur of light upon the darkness, indicated the position of the anchored ship.
It is imperative that now at once, while these stupendous events are still clear in my mind, I should set them down with that exactness of detail which time may blur.
And further, these dream trees were not a mere blur on my vision.
Had he had the eyes of a man, nearly two yards higher than his own from the deck, and had they been the trained eyes of a man, sailor- man at that, Jerry could have seen the low blur of Ysabel to the north and the blur of Florida to the south, ever taking on definiteness of detail as the Arangi sagged close-hauled, with a good full, port-tacked to the south-east trade.
San Francisco lay like a blur of smoke upon her heights.
She clung to him, unable to release herself, and he sat, half supporting her in his arms, as he gazed with unseeing eyes at the blur of the great city across the bay.
On the left the low-lying land stretched in a dim haze, rising here and there into a darker blur which marked the higher capes and headlands.
Right ahead a dark blur upon the water showed where the Aurora lay, and the swirl of white foam behind her spoke of the pace at which she was going.
The dull blur in front of us resolved itself now clearly enough into the dainty Aurora.
Whirlwind as he would, be could not damage Rivera, while Rivera through the blur and whirl, dropped him to the mat three times in succession.
The jungle was so far away that he could see only a dim, green blur below him, but just above and quite close was the sun.
The trees and houses still moved past him in the same indistinguishable blur.