What should not be used to cover a penetrating eye injury?

In the context of treating a penetrating eye injury, using a pressure patch is discouraged because it can exert inappropriate pressure on the eye, potentially exacerbating the injury or causing additional damage. Eye injuries can lead to various complications, including hemorrhage and globe rupture, and applying a pressure patch can worsen these conditions by creating pressure around an already compromised eye.

In contrast, the other options such as a rag, plastic wrap, and medical tape have more suitable applications. A rag can serve as a simple covering to protect the eye from debris, while plastic wrap can be used to shield the eye from environmental factors and minimize movement. Medical tape can be utilized to securely fasten a covering without applying too much pressure, reducing the risk of further injury. Each of these options is aimed at providing protection while allowing for the appropriate medical intervention to take place. Thus, avoiding a pressure patch is crucial for the safety and care of someone with a penetrating eye injury.