Sökning: "Apposition eye"

Hittade 4 avhandlingar innehållade orden Apposition eye.

  1. 1. Ommatidial adaptations for vision in nocturnal insects

    Författare :Rikard Frederiksen; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Gain of transduction; Information rate; Signal-to-noise ratio; Apposition eye; Optical sensitivity; Nocturnal insects; Superposition eye; Vision;

    Sammanfattning : Nocturnal vision is a demanding task for insects with small eyes. As it gets dimmer the noise imposed by the stochastic nature of photon arrival makes vision unreliable. Despite this, there are quite a number of animal species that are active at night and apparently see well. LÄS MER

  3. 2. Visual ecology of insect superposition eyes

    Författare :Pär A Brännström; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Animal physiology; tiger beetle; hawkmoth; mayfly; insect; visual ecology; eye design; vision; compound eye; Djurfysiologi;

    Sammanfattning : In the superposition compound eye each rhabdom (light sensitive unit) receives light through many ommatidial facets, while in the apposition compound eye every rhabdom receives light from a single facet. The superposition design increases photon capture, which is an advantage in dark environments. LÄS MER

  4. 3. Adaptations for nocturnal vision in insect apposition eyes

    Författare :Birgit Greiner; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; temporal and spatial summation; optical and neural adaptations; theoretical modelling.; Djurs anatomi och morfologi; Zoologi; dim light; vision; landmark navigation; nocturnal bees and wasps; Zoology; Animal anatomy; animal morphology;

    Sammanfattning : Due to our own preference for bright light, we tend to forget that many insects are active in very dim light. The reasons for nocturnal activity are most easily seen in tropical areas of the world, where animals face severe competition for food and nocturnal insects are able to forage in a climate of reduced competition and predation. LÄS MER

  5. 4. Multifunctional biomimetic materials for corneal regeneration

    Författare :Mohammad Mirazul Islam; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :;

    Sammanfattning : The cornea is the outermost layer of the eye, which is responsible for transmitting 95% of the incident light to the retina for vision and provides 70% of the focusing power of the eye. Corneal disease is a primary cause of blindness worldwide. LÄS MER