I have really bad vision; -7.0 to -7.5 in both eyes. Without glasses my focal point is about 3 inches from my face. At that range I can see quite a bit of fine detail that you'd never notice from even a foot away. In the past, before corrective lenses, I imagine 'fine jewlery maker' would be one of the few careers open to me, and that I'd be pretty good at it.

So the issue is not about having a higher density of rods and cones in the eye but about the focal point (which I think should be related to the lens). The closer to the surface the eye focus the sharper the image and more details are seen.

Same here. I am -8.0 and -8.5 with about a 2"-3" focus point and I can see very intricate detail that others have trouble seeing.

Wouldn't it be possible that the material deteriorated over time and so today it's harder to view the details than back when it was created?

Or they had techniques to miniaturize things.

Which is not out of the question; scaling a drawing up or down can be done with pretty simple tools (this is how a couple guys in Kentucky reproduced a Nazca-style giant figure back in the 1980s, with no access to flying saucers or mystically-levitating priests).

A pantograph is a simple machine that came along quite late. I can imagine a similar machine for carving, but I think it's quite easy to view the past with our own perspectives. The pantograph, and this speculative carving machine, are labor saving devices. I assume the Minoan sealstones were custom-made, one-of-a-kind items for those important enough to use them. While labor was cheap in most cases, those in need of this specialized skill were able to pay the cost.

No, the details were originally that small.

I think the question is less about size than about deterioration. By analogy - old documents are hard to read sometimes because ink has faded. So the question is more like: is the size the problem or is it the fidelity?

People can work on very tiny objects. Look up Diorama for a world devoted to creating intricate tiny objects.

See http://www.telegraph.co.uk/news/newstopics/howaboutthat/8315... - there was an excellent BBC Radio 4 program about this guy.

He works at night to limit traffic vibration, has learnt to slow his heart rate, gets Botox injections to stop from blinking, it's an obsession - not altogether healthy IIRC.

Very interesting.

I suspect they could have used curved polished bronze mirrors for magnification.

They may have access to a magnification technology but what would be the objection to the idea that human eye had a closer focus point 3000 years ago?

I'm open minded but in terms of evolution, 3000 years is a very short time, so changes in human physical capabilities requires specific and compelling evidence. In contrast, bronze age mirrors certainly existed and noticing and leveraging the effects of non-flat surfaces seems fairly inevitable to me given you only need to look at a spoon or something.

But it could be a one off. That is, someone was born with a mutation that gave them amazing levels of visual acuity, but didn't pass on that trait to children.

3000 years is to soon for significant changes in human DNA. Every population world wide would have to have very strong selective pressure for such a change to occur. Alternatively, everyone worldwide could simply have some environmental difference resulting in changes to the eye, but that also seems unlikely.

>3000 years is to soon for significant changes in human DNA.

Doesn't necessarily has to be DNA. Prevalence of fixed focus work, screens and monitors and reading, has made more people need glasses, in earlier ages, than 100 or 200 years ago for example...

Could it be the prevalence of ophthalmologists instead? I assume it was really hard to get good medical care100 to 200 years ago, not to mention the cost of glasses.

>Could it be the prevalence of ophthalmologists instead?

It's orthogonal. More doctors would mean more diagnosis. But more short distance indoors fixed focus screen work stress on the eyes would also mean more patients.

Too little time outdoors

Research has found that spending time playing outside as a child may reduce your chances of becoming short-sighted, and existing short-sightedness may progress less quickly.

This may be related to light levels outdoors being much brighter than indoors. Both sport and relaxation outdoors appear to be beneficial in reducing the risk of short-sightedness.

Excessive close work

Spending a lot of time focusing your eyes on nearby objects, such as reading, writing and possibly using hand-held devices (phones and tablets) and computers can also increase your risk of developing short-sightedness.

An "everything in moderation" approach is therefore generally recommended. Although children should be encouraged to read, they should also spend some time away from reading and computer games each day doing outdoor activities.

https://www.nhs.uk/conditions/short-sightedness/causes/

Not everyone worldwide has a computer. The environmental change I mentioned would need to be something like the change in CO2 levels to impact everyone.

You can't use "small details" to logically arrive a higher focus point. What use would humans have for intense detail, at a time when the world was far more dangerous at range? And even then, 3,000 years ago is less than a blink of an eye in terms of evolution. Without more examples of humans actually "needing" intense, closer focus, there's no way (even with a 3,000 year evolution window) they'd evolve closer focus just for... art.

Occam's razor is rather applicable here. Magnification would be way easier and more available. Even a polished bent sword magnifies.

But even if you can see the work, how do you stabilize the microtremors in the artists' hands?

You can use the equivalent of a mahlstick to guide your tool. Its one of those sticks with padded heads that painters rest their hand on to steady it.

https://en.wikipedia.org/wiki/Maulstick

It's really hard to know how detailed we're talking about based on this quote. But details can be created without being "clear" to the naked eye. But even if they needed to be clear, I suspect there were humans alive back then as well as today who, through genetic variance or lived experience, can see the details clearly whether you or the scientists who made this find are able to.

They couldn’t see the details because the object was 1,000s of years old, dirty and covered in limestone.

Below is a link from another poster.

http://magazine.uc.edu/editors_picks/recent_features/unearth...

Some ancient cultures trained children as engravers, who, after a lifetime of peering at tiny details, probably developed eye disorders and inability to see normally. This wouldn't be permitted today.