TJ-CEO
2007 , Vol 2 , Num 1
Optical Aberrations in Aphakia and Pseudophakia
Osmangazi Üniversite Tıp Fakültesi Göz Hastanesi A.D., Eskişehir, Doç. Dr.
In an ideal optical system, all rays of light from a point in the object plane would converge to the unique point in the image plane, forming a perfect image. The influences which cause different rays to converge to different points are called aberrations. For lenses made with spherical surfaces, rays which are parallel to the optic axis but at different distances from the optic axis fail to converge to the unique point. Aberrations can be cause blurring image even in the normal eye. Blurring image formation is seen high rate especially in aphakic and pseudophakic eye. For a single lens, spherical aberration can be minimized by changing the lens form. For multiple lenses, spherical aberrations can be canceled by correcting some elements. The use of different technique greatly reduces spherical aberration. A lens that includes an aspheric element is often called an aspherical lens. An aspheric lens is a lens whose surfaces have a profile that is neither a portion of a sphere nor of a circular cylinder. The aspheric lenses more complex surface profile can eliminate spherical aberration and reduce other optical aberrations compared to a simple lens. A single aspheric lens can replace a complex multi-lens system and the resulting device may be smaller and lighter than the multi-lens design.
Keywords :
Aphakia, pseudophakia, optic, lens, aberration, and aspheric