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blur

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

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

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 SLS, which is slated for a test flight this year, was shown in the series of photos released only with a large part of its body obscured and NASA Watch was the first to spot the blurred portions.
However, this model developed for natural blurred images does not perform well in some specific scenarios, such as faces, text, and low illumination images.
Yet one of the sensitive Israeli sites identified by blurred imagery is directly adjacent to Kfar Kila, on a hilltop partly surrounded by civilian homes in Israel's Metula.
This paper addresses the restoration of face image from a single blurred one without estimating blur kernel.
where K is blur kernel, [cross product] is convolution operator, L is latent unblurred image, and N is noise in blurred image.
Williams' testimony about how he wrote the song could be crucial to a federal jury that will soon decide whether "Blurred Lines'' improperly copied from Gaye's 1977 hit, "Got to Give It Up.''
Williams said he grew up listening to Gaye's music and was familiar with his song "Got to Give It Up," but did not use it as a basis for "Blurred Lines," which was a hit for him and collaborators Robin Thicke and T.I.
In this case, it needs to be estimated using the blurred image in order to apply deconvolution and obtain a better result.
(28) Louis Vuitton alleged trademark dilution by blurring, amongst other offenses, against Dooney & Bourke for their production of handbags that allegedly blurred the Louis Vuitton mark.
Two recognition methods for motion blurred images have been developed based on a relation between the moments of the blurred and the original images [16].
In fact, the lyrics to Lady Gaga's current single Do What U Want are arguably more offensive and misogamist than those in Blurred Lines.
Volunteers with normal vision were then presented with the blurred images and asked to describe what they saw.