It’s not our fly-swatting skills, insects vision is much better than we thought!
Ever wondered why the flies stuck in your home seem to be so good at avoiding your deadly swatter or rolled up newspaper? For years, scientists have not been able to answer this question, believing that insects vision was pretty blurry, leaving them unable to look at finer images. Recent research sheds new light on these little creatures and their ability to view surprisingly high-resolution images.
Insect Eyes vs Human Eyes
Here are some comparisons between the human and insect lens, impacting how they view objects:
- Have something called compound eyes. This means they have thousands of tiny lens-capped ‘eye-units’, which were believed to capture a low-resolution pixelated image of the surrounding world. In other words, blurry.
- This is the net-like feature, which we associate with their eyes
- Eyes differ completely, having just one large lens which gets bigger and smaller as it focuses on a point of interest depending on the amount of light available
- This change in lens shape allows us to keep an object in sharp focus whether close or far away
- In addition, our retinal photoreception (the megapixel “camera chip” in the eye) underneath our large lens is densely packed, allowing us to see high-resolution images
Whilst humans retinal photoreception underneath the lens is dense, in insects it is sparse. This, along with the other crucial differences mentioned above help us to understand why we were fooled into thinking insects vision was poor vision for all these years!
So what have we been missing?
Researchers from The University of Sheffield have made a huge breakthrough in their studies of insect eyes this September! Whilst we always thought the lack of photoreceptor cells underneath the lenses of an insect eyes caused poor eyesight, we have now learnt that this is not the case.
Why is that?
Well, new research has shown that these cells are able to move quickly and naturally in and out of focus as they view an image of the world around them. This happens at such a fast rate that we could not possibly see it with our naked eye. This is called microscopic light-sensor “twitching” .
This movement is natural for insects, correlating with their head/eye movements, as they view the world in saccadic bursts (a quick, simultaneous movement of both eyes between two or more phases of fixation in the same direction).
Mikko Juusola, Professor of Systems Neuroscience at the University of Sheffield and lead author of the study, says
“all animals with good vision, irrespective of their eye shape or design, see the world through fast saccadic eye movements and gaze fixations.’
Humans are included in this, and this research completely changes our former understandings of insects vision.
Next time an unwanted fly visits your home, don’t be disheartened when you can’t seem to shoo it away. They can see a lot more than we thought.
As for spiders, despite most having a whopping eight eyes, their eyesight generally is relatively poor...so there are really no excuses.
If you are interested in vision correction at Focus Clinics please call us on 0207 307 8250 to book a free consultation.