**Core Concept**
The eye undergoes several changes after death due to the breakdown of tissues and the effects of post-mortem autolysis. These changes can be observed during the autopsy process and are used in forensic pathology to estimate the time since death.

**Why the Correct Answer is Right**
One of the characteristic changes observed in the eyes after death is the separation of the retina from the underlying retinal pigment epithelium, known as retinal detachment. This occurs due to the liquefaction of the vitreous humor, which is the clear gel-like substance that fills the center of the eyeball. The liquefaction of the vitreous humor leads to a decrease in intraocular pressure, causing the retina to detach from the underlying tissue.

**Why Each Wrong Option is Incorrect**
**Option A:** The miosis (pupillary constriction) observed after death is a result of the decreased sympathetic tone and the accumulation of substances that cause pupillary constriction, such as acetylcholine and histamine. This is a common change observed in the eyes after death.

**Option B:** The conjunctival injection (redness) observed after death is due to the post-mortem changes in the blood vessels, including the breakdown of the blood-brain barrier and the release of histamine and other vasoactive substances. This is a common change observed in the eyes after death.

**Option C:** The corneal edema (swelling) observed after death is a result of the increased permeability of the corneal cells to water and the accumulation of fluid in the cornea. This is a common change observed in the eyes after death.

**Clinical Pearl / High-Yield Fact**
The time since death can be estimated by observing the changes in the vitreous humor, including the liquefaction of the gel-like substance and the release of potassium ions. This is known as the "vitreous potassium" test.

**Correct Answer:** D.