1. Introduction
2. Databases
2.1. Facial Databases
2.2. Iris Databases
2.3. Periocular Databases
3. Detection and segmentation of the periocular region
4. Recognition using periocular features
4.1. Global features
4.2. Local features
4.3. Literature review of periocular recognition works
5. Best regions for periocular recognition
6. Comparison and fusion with other modalities
6.1. Iris Modality
6.2. Sclera Modality
6.3. Face Modality
7. Soft-biometrics, gender transformation and plastic surgery analysis
8. Conclusions and future work