Substantial Limitation refers to a significant restriction or impairment that substantially limits a person's ability to perform a major life activity compared to the average person in the general population. It is a key concept in disability discrimination laws and regulations, such as the Americans with Disabilities Act (ADA). To be protected under the ADA, an individual must have a physical or mental impairment that substantially limits one or more major life activities, such as walking, seeing, hearing, speaking, or working.

Example
An employee with a visual impairment experiences a substantial limitation in their ability to see compared to the average person without such impairment. This limitation may affect their performance of certain job tasks that require visual acuity, such as reading printed materials or operating machinery that relies on visual cues. To accommodate the substantial limitation, the employer provides the employee with assistive technology, such as screen reading software or magnifying devices, to enhance their ability to perform job duties effectively.