ophthalmometer

American  

[of-thuhl-mom-i-ter, -thuh-, -thal-, op-] / ˌɒf θəlˈmɒm ɪ tər, -θə-, -θæl-, ˌɒp- /

noun

1. an instrument for measuring the reflection of an image on the surface of the cornea and other capacities of the eye, used chiefly for determining the presence and degree of astigmatism.

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Other Word Forms

• ophthalmometric adjective
• ophthalmometrical adjective
• ophthalmometry noun

Etymology

Origin of ophthalmometer

First recorded in 1835–45; ophthalmo- + -meter

Example Sentences

Helmholtz in his “Ophthalmometer” has employed Clausen’s principle, but arranges the plates so that both move symmetrically in opposite directions with respect to the telescope axis.

From Project Gutenberg

He investigated the optical constants of the eye, measured by his invention, the ophthalmometer, the radii of curvature of the crystalline lens for near and far vision, explained the mechanism of accommodation by which the eye can focus within certain limits, discussed the phenomena of colour vision, and gave a luminous account of the movements of the eyeballs so as to secure single vision with two eyes.

From Project Gutenberg