Automated Optical Inspection (AOI) is a machine-based technique typically used in the manufacturing industry of optics. It is used to inspect and certify optics such as flat, curved, coated and optics with different materials. Flat optics include windows, mirrors, etc., whereas curved optics include lenses with different curvatures. AOI uses optics to capture images for evaluating of potential faults such as dimensional defects and surface defects (e.g. digs, scratches, edge chips, bubbles, stains, impurity flaws, etc.). It provides quick and precise inspection to ensure that the product is of high quality without any manufacturing defects. With the increase in the complexity of products and them becoming smaller in size, to manually inspect them pose a serious challenge to workers and therefore AOI has a vital role to play in ensuring the products’ quality.