Shack-Hartmann sensors are optical devices used to measure wavefront distortions in light. They consist of an array of small lenses, called microlenses, that focus incoming light onto a detector. By analyzing the position of the focused spots, the sensor can determine how the wavefront has been altered, which is crucial for applications in astronomy, laser systems, and adaptive optics. These sensors are particularly valuable in correcting optical aberrations in telescopes and other imaging systems. They enable real-time adjustments to improve image quality, making them essential tools in fields like medical imaging and telecommunications, where precise light control is necessary.