It can be difficult to tell if you need new light seals without actually seeing your camera. However, some common signs of damaged or worn-out light seals are patches of visible dust inside the viewfinder and around the lens mount, as well as a foggy appearance in the viewfinder. Additionally, if you notice any gaps between the body and lens when it is attached, this could also mean that your light seals have become worn out over time. If any of these symptoms sound familiar then it may be time for you to replace your light seals.