Cognitive Load Theory is an instructional design theory that deals with how the human brain processes and stores information. It explains how information is transferred to long-term memory and how to identify small changes that will improve how quickly and effectively we can learn new information. Cognitive load refers to the amount of information the working memory can hold at any one given time. Cognitive Load Theory helps us to avoid overloading learners with more than they can effectively process into schemas for long-term memory storage and future recall. There are three types of cognitive load: intrinsic, extraneous, and germane. Intrinsic load refers to the inherent difficulty in processing information, regardless of how it is presented. Extraneous load refers to the way information is presented and how easy or difficult it is for a given learner to process it. Germane load is the cognitive load that is directly related to schema construction. Cognitive overload occurs when the combination of intrinsic, extraneous, and germane loads becomes overwhelming for the learner. Cognitive Load Theory was developed in the late 1980s out of a study of problem-solving by John Sweller. Sweller argued that instructional design can be used to reduce cognitive load in learners. Task-invoked pupillary response is a reliable and sensitive measurement of cognitive load that is directly related to working memory.