Expanded uncertainty. quantity defining an interval about the result of a measurement that may be expected to encompass a large fraction of the distribution of values that could reasonably be attributed to the measurand.
Introduction. 'Phantosmia' is the medical term for an imaginary odour (phantom smell) . It is also known as an olfactory hallucination. The smell is unique to the person and is usually unpleasant, spoiling the taste of any food or drink consumed.It can be in one or both nostrils.ess commonly, the cause of phantosmia is either nerve cells sending abnormal smell signals to the brain, or a problem with the brain itself. This may be the result of: 1  a disease affecting the nervous system, such as epilepsy, Parkinsonâs disease or Alzheimerâs disease. 2  a stroke.
astigmatism is usually the result of an irregular shaped cornea or lens the cornea is the transparent layer of tissue at the front of the eye the cornea should be regularly curved like the surface of a football but in cases of astigmatism it has an irregular curve more like the shape of a rugby ballegular astigmatism is where the cornea is curved more in one direction than the other it s more common than irregular astigmatism and can be corrected with glasses or contact lenses irregular astigmatism is where the curvature of the cornea isn t even across the surface of the eye