The US population is becoming increasingly older. Alongside the changing mental and physical capacities that accompany aging, reduced visual function is a common occurrence for older adults. Empathy is an important and useful skill for interior designers in that this ability is extremely helpful for understanding older adults' experience in the physical environment. A web-based vision simulator would be beneficial for interior design students in that students examine how their design can be seen by older adults with vision impairments by simply turning on the vision filter in their rendering. The main goal of this research is to understand the role of a web-based vision simulator on students' empathy for older adults with vision impairment. This study investigates the impact of the web-based vision simulator on the level of empathy of interior design students. In this study, the web-based vision simulator was introduced in a workshop during the semester and the pre/post survey was conducted with 21 senior interior design students. Research findings showed that this pedagogical intervention using a web-based vision simulator was successful in positively changing students' perspective-taking ability as an essential skill for gauging their empathy levels. Also, the web-based digital simulation was beneficial for students learning outcomes, that is, students revised their final design after using the simulator to provide a better environment for older adults with vision impairment.