**Core Concept**
Optic nerve injury can result from various causes such as trauma, ischemia, or compressive lesions, leading to visual disturbances and other associated symptoms. The optic nerve is responsible for transmitting visual information from the retina to the brain, and its dysfunction can affect both central and peripheral vision.

**Why the Correct Answer is Right**
Optic nerve injuries can present with a range of symptoms, including decreased visual acuity, visual field defects, color vision disturbances, and even loss of pupillary reflexes. The optic nerve's function is closely related to the retinal ganglion cells, which are responsible for transmitting visual signals to the brain via the optic nerve. The afferent pupillary defect, also known as a Marcus Gunn pupil, is a classic sign of optic nerve injury, where the pupils constrict upon covering the intact eye but dilate upon covering the affected eye.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because a decrease in visual acuity is a common feature of optic nerve injury, resulting from the transmission of distorted or incomplete visual information to the brain.
**Option B:** This option is incorrect because optic nerve injuries can indeed cause visual field defects, including central or peripheral scotomas, depending on the location and extent of the injury.
**Option C:** This option is incorrect because an afferent pupillary defect is a hallmark sign of optic nerve injury, indicating a disruption in the afferent visual pathway.

**Clinical Pearl / High-Yield Fact**
A key clinical correlation to remember is that the afferent pupillary defect is often more pronounced in patients with optic nerve injuries affecting the temporal retina, as these areas are more sensitive to visual field defects.

**Correct Answer: D.**