In this paper

the deflection aberration theory at extra-large deflection angle is studied by means of the curved axes theory. The second-order and the third-order aberration coefficients are given accordingly. The second-order and the third-order curved axes aberration and the screen raster in the uniform field are computed. The results obtained by the extra-large aberration theory

by the general third-order deflection aberration theory and by the analytic-formula have been compared. It has been shown that when the deflection angle is larger than 120°

the effects of the third-order curved axes aberration must be considered.