Worms aren't truly blind in the way humans understand it; they simply lack eyes with lenses that form images. Instead, they possess specialized cells called photoreceptors that detect light.
How Worms "See" Light
- Photoreceptors: These cells are sensitive to light and dark. They're distributed throughout a worm's body, particularly in the anterior (head) region.
- Light Detection, Not Vision: These receptors don't form images. They tell the worm whether it's in a brightly lit environment or a dark one.
- Survival Mechanism: This light sensitivity is crucial for survival. Worms need to stay underground in moist, dark environments to avoid dehydration and predators.
Why No Eyes?
- Evolutionary Adaptation: Worms evolved to thrive in soil. Image-forming eyes wouldn't be particularly useful in this environment.
- Simplicity: A simple light-detecting system is sufficient for their needs and is less energy-intensive to develop and maintain.
Analogy
Imagine you're wearing a blindfold but can still sense if someone turns on a bright light in the room. That's similar to how a worm perceives light. It doesn't see shapes or images, but it knows whether it's exposed to light.
