Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Excellent Underwater Vision Examined by Scientists from Lund

15.05.2003


We humans are poorly adapted for underwater vision. However, the Moken peoples of south-east Asia manage to collect shells, clams and sea cucumbers using no visual aids when diving to a depth of 3 or 4 metres. Scientists from Lund University in Sweden have now measured the visual acuity of these children and have found that their ability to see well underwater is not a myth: their acuity in this environment is indeed superior to that of European children. The scientists have also found an explanation for this phenomenon.



The results are presented in the new issue of the prestigious scientific journal Current Biology. Anna Gislén and Marie Dacke from the Department of Cell and Organism Biology have travelled several times to the Surin Islands (Thailand) where the Moken tribe live. These people are the so-called sea-gypsies, who for thousands of years have lived on their boats and collected food from the ocean. Some of them have settled down in houses built on three metre high stilts by the shore. At high tide the Moken can dive directly into the water from their houses.

Gislén and Dacke have performed a series of visual tests on the Moken children. Using an experimental apparatus placed under the surface, the children viewed striped patterns that were presented either horizontally or vertically. By using thinner and thinner stripes they could determine the resolution limit of the children.


”Underwater, Moken children can resolve stripes that are twice as fine as the finest seen by European children”, says Anna Gislén. ”We asked ourselves if this was due to a biological, possibly genetic, difference or if it was due to learning. For instance, we examined their eyes in detail, but could find no evidence that their corneas had a different curvature than the corneas of European children. Neither was there any evidence that the Moken children had better acuity on land.”

Was there something that these children did underwater that gave them better acuity? Under normal circumstances the pupil opens underwater to let in more light. But the pupils of Moken children constrict under water. The effect is the same as choosing a smaller aperture in a camera: focal depth is increased and resolution is improved. The Moken children also accommodate maximally, that is, the muscles controlling the lens are constricted and the lens changes shape, thus increasing the refraction of light.

”We are currently doing a follow-up study on Swedish children. Even though the study is not yet finished, it does seem that children can learn to adapt their eyes for better underwater vision”, says Marie Dacke.

Göran Frankel | alfa
Further information:
http://www.lu.se

More articles from Life Sciences:

nachricht Phage capsid against influenza: Perfectly fitting inhibitor prevents viral infection
31.03.2020 | Forschungsverbund Berlin

nachricht A 'cardiac patch with bioink' developed to repair heart
31.03.2020 | Pohang University of Science & Technology (POSTECH)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Physicist from Hannover Develops New Photon Source for Tap-proof Communication

An international team with the participation of Prof. Dr. Michael Kues from the Cluster of Excellence PhoenixD at Leibniz University Hannover has developed a new method for generating quantum-entangled photons in a spectral range of light that was previously inaccessible. The discovery can make the encryption of satellite-based communications much more secure in the future.

A 15-member research team from the UK, Germany and Japan has developed a new method for generating and detecting quantum-entangled photons at a wavelength of...

Im Focus: Junior scientists at the University of Rostock invent a funnel for light

Together with their colleagues from the University of Würzburg, physicists from the group of Professor Alexander Szameit at the University of Rostock have devised a “funnel” for photons. Their discovery was recently published in the renowned journal Science and holds great promise for novel ultra-sensitive detectors as well as innovative applications in telecommunications and information processing.

The quantum-optical properties of light and its interaction with matter has fascinated the Rostock professor Alexander Szameit since College.

Im Focus: Stem Cells and Nerves Interact in Tissue Regeneration and Cancer Progression

Researchers at the University of Zurich show that different stem cell populations are innervated in distinct ways. Innervation may therefore be crucial for proper tissue regeneration. They also demonstrate that cancer stem cells likewise establish contacts with nerves. Targeting tumour innervation could thus lead to new cancer therapies.

Stem cells can generate a variety of specific tissues and are increasingly used for clinical applications such as the replacement of bone or cartilage....

Im Focus: Artificial solid fog material creates pleasant laser light

An international research team led by Kiel University develops an extremely porous material made of "white graphene" for new laser light applications

With a porosity of 99.99 %, it consists practically only of air, making it one of the lightest materials in the world: Aerobornitride is the name of the...

Im Focus: Cross-technology communication in the Internet of Things significantly simplified

Researchers at Graz University of Technology have developed a framework by which wireless devices with different radio technologies will be able to communicate directly with each other.

Whether networked vehicles that warn of traffic jams in real time, household appliances that can be operated remotely, "wearables" that monitor physical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“4th Hybrid Materials and Structures 2020” takes place over the internet

26.03.2020 | Event News

Most significant international Learning Analytics conference will take place – fully online

23.03.2020 | Event News

MOC2020: Fraunhofer IOF organises international micro-optics conference in Jena

03.03.2020 | Event News

 
Latest News

Phage capsid against influenza: Perfectly fitting inhibitor prevents viral infection

31.03.2020 | Life Sciences

A 'cardiac patch with bioink' developed to repair heart

31.03.2020 | Life Sciences

Artificial intelligence can speed up the detection of stroke

31.03.2020 | Medical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>