Prism scopes, literally speaking, are fixed magnification optics that have a prism inside, which means that their constructions are much more compact and robust than a traditional scope. Their magnification is fixed and low: 1x, 2.5x, 3x, 4x, or 6x. And they are usually equipped with an illuminated and etched reticle, users can choose between green and red illumination. But what exactly enables them to stand out from traditional scopes? The answer is, their diopter adjustment setting. With red dot sights, users with astigmatism may suffer from an unclear image of the reticle, but with prism scopes, they can always adjust the diopter to see a crisp reticle!
However, the fixed and low magnification also means that prism scopes have a relatively small eye-box and limited eye relief, which are perhaps the only downsides.
