Thirty years ago, Gobin and Bierlaagh developed the simultaneous horizontal and cyclovertical strabismus surgery that became a recognized, albeit much debated method, but no manual on the subject was available until now. The book is aimed at ophthalmologists interested in strabismus. It is also intended for orthoptists, in view of the importance of examining ocular motility. Although the ophthalmologist remains responsible for the surgical indication, the active participation of the orthoptist is advantageous. The analysis of incomitances of the eye movements is discussed extensively, as it is the keystone of simultaneous surgery. For the same reason, great attention is given to the surgical indications. The chapter on oculomotor disturbances is completed with a series of examples of the most common motility disorders and the indications for their surgical treatment. Surgery is covered in detail. Primary surgery is discussed in the same section as surgery for under and overcorrection.Since a correct sequence of the different surgical acts is essential for a smooth intervention, the technique of operating rectus as well as oblique muscles is presented in a clear, step-by-step manner. The last chapter deals with the complications such as limitation of duction, postoperative diplopia and the change in palpebral fissure. The book contains approximately 380 black and white illustrations in 270 figures and 94 colour plates, illustrating surgical techniques. The work is based on an analysis of more than 6500 cases.