Which two ocular structures can touch if the anterior chamber is flat?

When the anterior chamber of the eye is flat, it typically indicates a loss of aqueous humor, which can result in the iris and cornea coming into contact with one another. The anterior chamber is the space between the cornea and the iris, and when it becomes flat, the normal separation between the cornea and iris is diminished, leading to possible touching.

In this scenario, the iris and cornea can touch due to the reduction of space that the anterior chamber provides. This interaction can be clinically significant as it can lead to conditions such as angle-closure glaucoma or other complications, as contact can hinder normal fluid drainage and production.

While the other options describe relationships between different ocular structures, they do not directly relate to the condition of the anterior chamber being flat. For instance, while the lens and retina are important structures in the eye, they are not located in the anterior chamber, which is more relevant to this question. Similarly, although the iris and lens are positioned close to one another, the direct contact in the event of a flat anterior chamber is more pertinent between the iris and cornea.