What does anastigmat mean?
An anastigmat is a photographic or optical lens that has been corrected for astigmatism, an aberration in which light rays passing through different meridians of a lens fail to converge at a single focal point, blurring off-axis parts of an image. By combining lens elements with carefully calculated curvatures and refractive properties, an anastigmat brings rays into common focus, producing sharp detail across the entire field rather than only at the centre. The term derives from Greek roots: the prefix 'an-' expresses negation, and 'stigma' refers to a point, so the word literally denotes freedom from the point-like defect of astigmatism. Anastigmat lenses became commercially significant in the late nineteenth and early twentieth centuries, when designs such as symmetrical doublets made high-quality photography widely accessible. Today the word survives chiefly in optics terminology, vintage camera descriptions, and the history of photographic technology, with 'anastigmatic' serving as its adjective form.
nounA photographic or optical lens that has been corrected for astigmatism, so that light rays in different planes come to a focus at the same point and produce sharp images across the field.
- A lens corrected for astigmatism, giving sharp focus across the whole image field.
"The camera's new anastigmat lens delivered crisp detail from the centre of the frame to its edges."
"Early twentieth-century cameras were prized for their fast anastigmat lenses, which rendered portraits with unprecedented clarity."
"The optician explained that unlike the eye affected by astigmatism, the camera's anastigmat focuses all rays to a single point."
The standard plural follows regular English noun formation; the plural is uncommon outside technical catalogues and inventories.
"The workshop stocked several anastigmats of differing focal lengths."
The word 'anastigmat' literally means 'without a point of blur' — it was coined to name the lens that finally let photographers capture sharp corners as well as sharp centres.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of anastigmat
The word 'anastigmat' comes from Greek elements: the privative prefix 'an-' ('not') combined with 'stigma' ('a point, mark'), reflecting the idea of a lens without the point-defect of astigmatism. It was formed in the modern era of optics, alongside the related terms 'astigmat' and 'astigmatism', as lens designers sought names for corrected optical systems. Its sibling words include 'astigmatic' and 'stigma', all drawing on the same Greek root.
Related word forms
How anastigmat is actually used
A technical term used mainly in optics, photography history, and lens manufacturing literature; rare in everyday conversation. The related adjective 'anastigmatic' describes the property of being free from astigmatism.
Easily confused with anastigmat
An astigmat is a lens that still suffers from astigmatism, whereas an anastigmat is one that has been corrected for it.
Astigmatism is the optical defect itself — blurred vision caused by unequal curvature of the eye's surfaces — while an anastigmat is a manufactured lens designed to eliminate that defect.