GENERATION OF 3RD-ORDER SPHERICAL AND COMA ABERRATIONS BY USE OF RADIALLY SYMMETRICAL 4RTH-ORDER LENSES

We have extended the method of Alvarez [J. Am. Optom. Assoc. 49, 24 (1 978)] to generate a variable magnitude of third-order spherical and/or coma aberration by using a combination of fourth-order plates with a magnification system. The technique, based on the crossed-cylinder abe rroscope, is used to measure the wavefront aberration generated by the plates. The method has been applied to correct the third-order spheri cal aberration generated by an artificial eye as well as the coma prod uced by a progressive addition ophthalmic lens. The simplicity of the method and its relatively low cost make it attractive for partial corr ection of the aberrations of the eye. (C) 1998 Optical Society of Amer ica.