This chapter covers the basic principles of artificial intelligence (AI) and its growing role in modern healthcare, especially in ophthalmology. It traces AI’s development from early ideas like the Turing Test to today’s advances in machine learning (ML), deep learning (DL), and artificial neural networks (ANNs). The discussion shows how these technologies mimic human thinking to perform complex analysis and prediction tasks. A thorough overview is given of AI models, data needs, and the training processes that help create smart decision-making systems. The chapter also looks at real-world uses of AI in medical imaging, clinical decision support, precision medicine, robotic surgery, telemedicine, and patient interaction via AI chatbots. Ethical and regulatory issues such as algorithmic bias, data privacy, and the need for human oversight are also explored. By explaining both what AI can and cannot do, this chapter lays the technical and conceptual foundation needed to understand how AI is used in ophthalmic and broader healthcare applications.