Ciliary muscles , choroid , fovea , gustatory cells

Answer

### Step-by-Step Solution

1. **Identify the Terms**: The terms given are ciliary muscles, choroid, fovea, and gustatory cells.

2. **Define Each Term**:
- **Ciliary Muscles**: These are smooth muscles located in the middle layer of the eye. Their primary function is to control the shape of the lens for accommodation, allowing the eye to focus on objects at varying distances.
- **Choroid**: This is a vascular layer of the eye located between the retina and the sclera. It contains connective tissues and is responsible for maintaining the volume and temperature of the eye.
- **Fovea**: The fovea is a small pit located in the macular region of the retina. It is about 1.5 mm in size and is responsible for providing the clearest vision, particularly for activities like reading and driving.
- **Gustatory Cells**: These are not part of the eye; instead, they are taste buds located on the tongue and other areas of the mouth. They are responsible for the sense of taste.

3. **Determine the Odd One Out**:
- The first three terms (ciliary muscles, choroid, and fovea) are all components of the eye, while gustatory cells are related to taste and are not part of the eye structure.

4. **Conclusion**: The odd one out is **gustatory cells** because they are not associated with the eye, unlike the other three terms.