A cow sees the full moon. A 5 year child looks at the full moon.

Looking implies that the individual images formed by the individual light receptors are:
a: continuously integrated into a single dynamic images,
b: holistic implications (to the “self”) of the changing integrated images are assessed and
c: appropriate (at & for that time) responsive motor actions are executed.

Vasanth

1. Bacteria can respond to light, but they don’t use opsins (the photoreceptors in our eyes). So it’s possible opsins were serving some unknown function for the lamp shells, while some other set of proteins was sensing light.

Seeing would mean extracting information from light using opsin photoreceptors.

2. There are eyes that form images, and eyes that detect light direction. Since they are homologous, it’s fair to call them eyes.

But I’m confused by a few things:

1. in the article, Dr. Oakley is cautious:

But he cautioned that just because the photoreceptor gene was active in the early embryo, that did not necessarily mean that the lamp shells were able to see. “Other possible photoreceptive mechanisms should also be ruled out,” Dr. Oakley said. “Correlation does not mean causation.”

What would qualify as “seeing?”. What type of organism response?

2. (probably related the last question) What qualifies as an “eye”? is it image formation? Behaviorally directed response to light? Or any form of response to light (as in the ‘pineal eye’)?