Most of the measurement procedures used in this study are non-invasive and all are used in standard routine clinical practice, the benefit/risk ratio appears acceptable.~However, a capsule tension ring will be used. A CTR is not used routinely, usually only in cataract operations in which the lens capsule is not stable enough - in other words, for stabilization. The insertion of the CTR is problem-free in most cases. In extremely rare cases, however, the lens capsule may be injured. And document complications will be collected, report them in a final paper. The CTR used in the study is a standard device and CE-marked device. Studies using CTR showed that it is beneficial in difficult cases.~Gonioscopy after cataract surgery will be performed after 1 week. At this time point the wound is already sealed and there appears to be no increased risk to the patient. In the first study performed in a similar fashion in 1999 gonioscopy was performed one day after surgery.~Aim of this study is to predict the diameter of the capsular bag using pre-operative optical biometry findings.~This is a prospective, observer-blind and monocentric study that includes patients scheduled for cataract surgery. Recruitment will take part on the day of pre-assessment. For each patient only one eye will be included.~In total 50 eyes of 50 patients will be included, of which at least 5 eyes with an axial eye length below 22.5mm and 5 eyes with an axial eye length above 25.0mm.
Aim of this study is to assess whether a high-resolution scan of the crystalline lens before surgery may be helpful in predicting post-operative capsule bag diameter.