Diatom shell (IMAGE) Optica Caption A new optical study reveals how the glass-like shells of diatoms help these unicellular organisms perform photosynthesis even in dim conditions. Their shells contain holes that change the behavior of light depending on their size, spacing and configuration. Credit Santiago Bernal, McGill University Usage Restrictions None License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.