[jdthedisciple]

Great article but I don't get their insistent on "inefficiency":

They start out saying oxygen vessels partially and subtly occludes vision.

So the bird's eye doesn't suffer from this disadvantage.

In other words: It uses 15x more energy but presumably also sees 15x sharper and more into the distance than our human eye.

Sounds proportional at most, but certainly not inefficient for the bird's purposes?

[jibal]

Every mention of efficiency is about the chemical process, not about vision as such.

> anaerobic glycolysis that is significantly less efficient than oxygen-powered metabolism

> Oxygen molecules make energy production in cells extremely efficient.

> the presence of oxygen makes energy extraction from a single glucose molecule 15 times as efficient, and sometimes more.

> This energetic ability is powered by an inefficient metabolism.

> This suggested that the strange structure wasn’t bringing oxygen into the bird’s retina; rather, it was helping to pump glucose in, thereby enabling the less efficient anaerobic process.

[jdthedisciple]

You cannot ignore the tradeoffs and the output produced:

> Though we normally can’t perceive them, these vessels always occlude a portion of what we see, and for an important reason.

Efficiency is input / output, not just input.

15x input / 15x output is just as efficient as 1x input / 1x output.

[jibal]

You complained about the article's talk about "inefficiency" -- you quoted it. But as I noted, THEIR mention of efficiency/inefficiency was ALWAYS about the chemical process, not about efficiency of vision. Now you're totally moving the goalposts. I don't understand why you're playing such an obviously absurd game but I will leave you to it.

[jdthedisciple]

?? why the nastiness?

I'm not moving goalposts. My 2nd comment just adds detail, which i hoped the reader would manage to infer based on my 1st one. That's all.

My point is it's like saying a car is more inefficient than a bicycle because it uses (more) fuel... totally ignoring that it also gets you much further and that too much faster.

Whereas a valid, to me, criticism would be that a particular car is less efficient than another car bc it burns more gas, when both do about as good a job.

[mhb]

I don't think the article asserts that the better bird vision is primarily due to the absence of occluding blood vessels, although that is an advantage.

Scientists noted that the bird eye produces good results with a less efficient process. This article is only about the explanation for that. Presumably they would have been just as interested if a human level eye also operated without oxygen.