Search results
Results from the WOW.Com Content Network
The arthropods ancestrally possessed compound eyes, but the type and origin of this eye varies between groups, and some taxa have secondarily developed simple eyes. The organ's development through the lineage can be estimated by comparing groups that branched early, such as the velvet worm and horseshoe crab to the advanced eye condition found ...
Compound eye of Antarctic krill as imaged by an electron microscope. A compound eye is a visual organ found in arthropods such as insects and crustaceans.It may consist of thousands of ommatidia, [1] which are tiny independent photoreception units that consist of a cornea, lens, and photoreceptor cells which distinguish brightness and color.
Hogna wolf spider (family Lycosidae) showing the enlarged posterior median eyes typical of the family. The eyes of spiders vary significantly in their structure, arrangement, and function. They usually have eight, each being a simple eye with a single lens rather than multiple units as in the compound eyes of insects. The specific arrangement ...
This can only be countered by increasing lens size and number. To see with a resolution comparable to our simple eyes, humans would require compound eyes that would each reach the size of their heads. Compound eyes fall into two groups: apposition eyes, which form multiple inverted images, and superposition eyes, which form a single erect image.
A simple eye or ocellus (sometimes called a pigment pit [1] [2]) is a form of eye or an optical arrangement which has a single lens without the sort of elaborate retina that occurs in most vertebrates. These eyes are called "simple" to distinguish them from "compound eyes", which have multiple lenses. They are not necessarily simple in the ...
The butterfly compound eye consists of multiple ommatidia, each of which consist of nine photoreceptor cells (numbered from R1–R9), and primary and secondary pigment cells. [5] Nymphalid butterflies have the simplest eye ommatidium structure, consisting of eight photoreceptor cells (R1–R8) and a tiny R9 cell organized into a different tier.
Consequently, many molluscs may have a multitude of eyes in more unlikely places, such as along the edge of their shell. [1] Chitons have a dispersed network of tiny eyes over the surface of their shells which may act together as a compound eye. [1] Many gastropods have stalked eyes; the eye can be retracted into the stalk itself in the ...
Each eye may have up to 17,000 individual light receptors , which in combination provide a broad mosaic view of the surrounding area. [6] One tropical Asian family, the Amphitheridae, has compound eyes divided into two distinct segments. [13] [20] The eyes are usually smooth but may be covered by minute hairs.