1.1. Prelude from carrots1.2. Liquid crystals, optics and defects: a long-standing trilogy1.3. Polarization optics of liquid crystals: basic ingredients1.4. Liquid crystal reorientation under external fields1.5. Customary optics from liquid crystal defects1.6. From regular to singular optics1.7. Advent of self-engineered singular optical elements enabled by liquid crystals defects1.8. Singular optical functions based on defects: a decade of advances1.9. Emerging optical functionalities enabled by liquid crystal defects1.10. Conclusion1.11. References