Under what condition, an image formed on this part of the retina cannot be detected by the brain?

Explanation

To answer the question "Under what condition, an image formed on this part of the retina cannot be detected by the brain?" we need to understand the concept of the blind spot in the human eye.

### Step-by-Step Solution:

1. **Understanding the Retina**: The retina is a layer at the back of the eye that contains light-sensitive cells (photoreceptors) which convert light into electrical signals. These signals are then sent to the brain via the optic nerve.

2. **Identifying the Blind Spot**: The blind spot is a specific area on the retina where there are no photoreceptors. This area is located where the optic nerve exits the eye. Since there are no light-sensitive cells in this region, it cannot detect any images.

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