In interior architecture, one of the main purposes of light is to create comfortable and functional spaces according to user needs. Light provides individuals to understand, get information for visual tasks and it affects how they experience and behave in the environment. Desired illuminance levels are required for visual comfort and task efficiency. This study analyzes the effects of different illuminance levels of light emitting diode (LED) and organic light emitting diodie (OLED) lights on user visual comfort and reading performance. An experiment was conducted with eighty interior architecture students at Çankaya University. Six lighting scenarios were created with LED and OLED lighting sources that assessed six visual comfort criteria. The experimental setting consisted of three different illuminance levels, as 200, 500 and 800 lx. The results revealed that different illuminance levels were found more comfortable for different visual comfort criteria, but the illuminance level of 500 lx was visually more comfortable than the other illuminance levels. The illuminance level of LED 200 lx was visually more comfortable than LED 800 lx. OLED light was found visually more comfortable than LED light. In addition, participants read slower under the illuminance level of LED 200 lx. It was concluded that illuminance levels of light effect user’s visual comfort and reading performance. This study provides a basis to recommend the preferred illuminance level for LED and OLED light during a reading performance.