(On seed) lateral depression or bulge, mainly in Leguminosae/Fabaceae, most evident in subfamily Papilionoideae, an area of weakness, sometimes partially open, where water initially penetrates the otherwise impenetrable testa.
The transparent, double convex (outward curve on both sides) structure suspended between the aqueous and vitreous; helps to focus light on the retina.
The transparent body through which images are focused on the retina.
The part of the eye behind the iris and pupil, which focuses light coming from the cornea onto the retina.
A piece of shaped glass or plastic which forms part of a pair of spectacles or microscope.
Jelly-like disc that bends light entering the eye.
In anatomy, transparent crystalline structure of the eye, behind the pupil, that helps to focus light onto the retina. (In a cataract, the lens becomes cloudy.)
The transparent structure within the pupil of the eye that helps focus incoming light; also called the crystalline lens. Light entering the eye is bent (focused) first by the cornea, which directs the light through the pupil (the opening in the black center of the eye). The light then passes through the crystalline lens, which bends it into final focus. Held in place by fibers called the ciliary body, the crystalline lens thins to focus on objects in the distance and thickens for close vision.
The transparent crystalline structure situated behind the pupil of the eye and enclosed in a thin transparent capsule. It helps to refract incoming light and focus it onto the retina.
A transparent refracting medium; usually made of glass.
The transparent structure just behind the iris that focuses light on the inner, back side of the eye.
In television and photographic cameras, there exists a meticulously calibrated assembly of optical elements within a mount. This assemblage is designed to achieve precise correction and is instrumental in forming an accurate image of the subject on a light-sensitive surface, facilitating its reproduction.
The inner component of the eye accountable for focusing, also referred to as the crystalline lens (to differentiate it from the cornea, which is another type of lens). This lens is a circular, flexible, see-through structure located behind the iris and hung by delicate fibers from the ciliary body. Its front surface is slightly less curved than its back surface.
The lens accurately focuses light onto the retina, which is the layer of light-sensitive cells that coats the inside of the eyeball. The ciliary body’s muscles influence the lens, modifying its curvature and consequently adjusting its focus. This enables clear vision of objects whether they are close or far away.
A prevalent condition that can impact the lens is cataract, characterized by the gradual opaqueness of the lens tissue, leading to impaired vision. Additional potential issues include lens dislocation and aphakia, which refers to the absence of the lens.
A clear material, such as glass, crystal, or plastic, crafted to either focus or disperse rays of light, constitutes a lens. Lenses are categorized based on their surface shape, their intended function, or the tint employed to filter specific portions of the light spectrum.