Clarity of Image

Clarity of Image is just that. If the observer senses anything other than a perfectly clear image, the optical system is compromised in some way. There may be fuzziness at the edges of observed objects, a general blurriness or cloudiness to the field, or the lack of clarity may be specifically in limited areas of the field. Any lack of clarity which interferes with resolution in the field of view is unacceptable.

Such problems are usually the result of defective optics, poor coatings on lenses, or inappropriate prescription in the system for the user. If a system lacks clarity and is supposed to include a specific prescription adjustment, the surgeon should consult an optometrist to confirm that the prescription is correct and that the lenses were correctly ground and adjusted. The best way to determine clarity of image in magnification systems is to look through the lens(es) at a black and white image, preferably one with sharp lines of demarcation. An Amsler Grid (white lines on a black background) is an ideal target for determining Clarity of Image.

If colors are observed on the black and white Amsler field, the image may still present as clear in spite of these Chromatic Aberrations.

Levels of Clarity of Image:

3 = Excellent definition (here shown as a view through telescopes of an Amsler grid)



2 = Good definition



1 = Fair definition



0 = Poor Definition