**Core Concept**
The ideal storage media for eye tissues, such as corneal grafts, require a specific pH and osmolarity to prevent damage to the cells and maintain their viability for transplantation. The storage media should mimic the natural intraocular environment as closely as possible.

**Why the Correct Answer is Right**
The ideal pH for storage media is slightly alkaline, around 7.4, which is close to the natural pH of the cornea. This pH helps to maintain the structural integrity of the corneal cells and prevents excessive enzymatic activity. The osmolarity of the storage media should be isotonic, around 290-300 mOsm/L, which is similar to the natural osmolarity of the cornea. This helps to prevent cellular swelling or shrinkage due to osmotic imbalances.

**Why Each Wrong Option is Incorrect**
**Option A:** A pH of 6.8 is too acidic and can cause cellular damage and necrosis.
**Option B:** A pH of 7.8 is too alkaline and can lead to excessive enzymatic activity and tissue degradation.
**Option C:** An osmolarity of 250 mOsm/L is too hypotonic and can cause cellular swelling and lysis.
**Option D:** An osmolarity of 350 mOsm/L is too hypertonic and can cause cellular shrinkage and dehydration.

**Clinical Pearl / High-Yield Fact**
Remember, the ideal storage media for eye tissues should be adjusted to match the specific needs of the tissue being stored, and the pH and osmolarity should be carefully controlled to prevent damage to the cells.

**Correct Answer: C. 7.4, 290-300 mOsm/L**