The present disclosure is generally directed towards methods and devices for reducing or eliminating reflection-illuminated artifacts. The methods and devices in several embodiments can include providing a transparent lens cover with a blocking member for reflecting or absorbing internally-reflected light. The lens cover can be attached at the distal end of an endoscope, cannula, and/or lumen in some embodiments. Alternatively, the lens cover can be a permanent part of the endoscope, lumen, and/or cannula.