Biconvex structureEpithelium cellsPosteriorPhakic intraoVertebratesPostoperativeCornealRefractive powerThicknessCollamerCiliaryIrisConcaveCorneaFront of the lensImplantationIntraocularVitreousHumansCapsuleRetinaCataractPowerShapeStructuresCorrectEyesCellsImagePointEnterLightSurfaceCameraSimilarPresenceMaintainOrder
Biconvex structure1
- The lens, or crystalline lens, is a transparent biconvex structure in most land vertebrate eyes. (wikipedia.org)
Epithelium cells1
- As ions, nutrients, and liquid enter the lens from the aqueous humor, Na+/K+-ATPase pumps in the lens epithelial cells pump ions out of the lens to maintain appropriate lens osmotic concentration and volume, with equatorially positioned lens epithelium cells contributing most to this current. (wikipedia.org)
Posterior5
- In land vertebrates the lens is flatter on its anterior side than on its posterior side, while in fish the lens is often close to spherical. (wikipedia.org)
- The front and back of the lens are referred to as the anterior and posterior "poles", like the North and South poles. (wikipedia.org)
- However, for a complete description of the effective corneal power (spherical and cylindrical) the posterior surface of the cornea also needs to be considered. (phacooptics.net)
- The spherical ICL (sICL) has a plano-concave geometry with a single radius of curvature in the posterior surface whereas the toric ICL (tICL) has a meridional variation of the curvature in the anterior surface to generate the astigmatic correction. (biomedcentral.com)
- Light is further converged by the crystalline lens located posterior to the iris. (medscape.com)
Phakic intrao1
- They include phakic intraocular lenses and a procedure like clear lens extraction with high-plus power lens implantation. (medscape.com)
Vertebrates3
- In many fully aquatic vertebrates such as fish other methods of accommodation are used such as changing the lens's position relative to the retina rather than changing lens shape. (wikipedia.org)
- A subclass of crystallins that found in the lens (LENS, CRYSTALLINE) of VERTEBRATES. (lookformedical.com)
- A class of crystallins that provides refractive power and translucency to the lens (LENS, CRYSTALLINE) in VERTEBRATES. (lookformedical.com)
Postoperative2
- Postoperative spherical equivalent was within ± 0.50D in 66% and 83% of the eyes, respectively implanted with sICL and tICL. (biomedcentral.com)
- A relevant postoperative parameter contributing to the normal physiological behaviour regards to the distance between the ICL and the anterior surface of the crystalline lens, namely the vault [ 2 ]. (biomedcentral.com)
Corneal1
- Refractive corneal surgery had the potential to rival the visual results of phakic lens implants, as it can correct both the spherical error and the cylindrical error. (medscape.com)
Refractive power1
- The refractive power of a younger human lens in its natural environment is approximately 18 dioptres, roughly one-third of the eye's total power of about 60 dioptres. (wikipedia.org)
Thickness3
- PhacoOptics ® IOL power calculation incorporates the latest generation ELP (estimated lens plane) prediction algorithms, including the patented C-constant concept by which the physical IOL position is predicted from the preoperative anatomy of the crystalline lens (anterior chamber depth and lens thickness). (phacooptics.net)
- The GEE identified the ICL size minus the anterior chamber width, the ICL spherical power and ICL central thickness as significant factors influencing the vault. (biomedcentral.com)
- 3) Reducing the thickness of the spectacle lens without changing the lens power. (examyear.com)
Collamer3
- Two types of intraocular lenses (IOLs) are mainly used in hyperopes: the precrystalline lens implant (implantable Collamer lens) and the iris-fixated lens (Artisan lens). (medscape.com)
- To determine the influence of implantable collamer lenses (ICL) geometry, i.e. spherical and toric on the vault, and report the refractive and visual outcomes of patients bilaterally implanted with the two ICL geometries. (biomedcentral.com)
- Refractive surgery with implantation of phakic lenses such as Implantable Collamer Lenses (ICL, STAAR Surgical AG) has been shown to be a safe and efficient method for the correction of a wide range ametropias [ 1 ]. (biomedcentral.com)
Ciliary6
- The lens is held in place by the suspensory ligaments (Zonule of Zinn), attaching the lens at its equator to the rest of the eye through the ciliary body. (wikipedia.org)
- The crystalline lens of the eyes performs an crucial function in assisting the visible system to function extra effectively because of the reality that it works together with the ciliary muscle mass of the attention to convey distant and near items into clean cognizance. (daohangtiaozhuan.com)
- For instance, the action of the ciliary muscle mass on the lens effects within the converting of the form of the lens on the way to facilitate our eyes' capability to focus on distinct gadgets at unique distances. (daohangtiaozhuan.com)
- Take as an example, when we are looking at a far off object the motion of the ciliary muscle tissues on the eye lens creates its form from the point of view of a spherical shape this is thicker in nature. (daohangtiaozhuan.com)
- The lens is attached to the ciliary muscles. (assignmentpoint.com)
- By carefully adjusting the lenses shape, the ciliary muscles assist the eye in the critical task of producing an image on the back of the eyeball. (assignmentpoint.com)
Iris11
- The lens is located towards the front part of the vertebrate eye called the anterior segment which includes the cornea and iris positioned in front of the lens. (wikipedia.org)
- The "equator" is the outer edge of the lens often hidden by the iris and is the area of most cell differentiation. (wikipedia.org)
- The Crystalline lens of the eyes is located behind the iris of the eyes and is part of the visible machine that is located inside the choroid which is known as the middle layer of the eyes. (daohangtiaozhuan.com)
- In 1977, Worst designed and used a pure iris support lens. (medscape.com)
- This iris claw lens was fixed to the anterior surface of the iris independent of the pupil. (medscape.com)
- An iris claw lens is shown in the image below. (medscape.com)
- The iris claw lens for a phakic hyperopic eye, implanted in the eye of a blue-eyed patient. (medscape.com)
- Minimal essential iris fold in the lens claw exists for the purpose of fixation. (medscape.com)
- Jan Worst, the designer of the lens, considers the peripheral part of the iris as a silent area. (medscape.com)
- In 1986, Fechner used a negative-power iris claw lens for treating phakic myopes. (medscape.com)
- Such eyes are typically spheroid, filled with the transparent gel-like vitreous humour , possess a focusing lens , and often an iris . (knowpia.com)
Concave2
- Eyeglasses with concave lenses correct this problem by diverging the light rays before they enter the eye. (assignmentpoint.com)
- 1) A concave lens causes light passing through the periphery of the lens to be refracted more than when passing through its centre. (examyear.com)
Cornea1
- 1) Decreasing the distance between the spectacle lens and cornea. (examyear.com)
Front of the lens4
- At the front of the lens is the liquid aqueous humor which bathes the lens with nutrients and other things. (wikipedia.org)
- The cells of the lens epithelium form a thin layer between the lens capsule and the outermost layer of lens fibers at the front of the lens but not the back. (wikipedia.org)
- The lens epithelium is a single layer of cells at the front of the lens between the lens capsule and the lens fibers. (wikipedia.org)
- 4) It may be reduced by decreasing the aperture in front of the lens. (examyear.com)
Implantation1
- PhacoOptics1 ® is a powerful IOL power calculation and data management system for the ophthalmic lens surgeon to improve the refractive outcome of IOL implantation. (phacooptics.net)
Intraocular2
- An angle-supported lens has been used very rarely in hyperopes and has fallen out of fashion owing to associated complications related to increased intraocular pressure and loss of endothelial cells. (medscape.com)
- For the purpose of this article on eye globe anatomy, the eye will be divided into 2 sections: extraocular (ie, structures outside of the globe) and the ocular (ie, the globe and intraocular structures). (medscape.com)
Vitreous1
- Behind the lens is the jelly-like vitreous body which helps hold the lens in place. (wikipedia.org)
Humans1
- The ultimate goal of such an anatomy is to allow humans to focus images on the back of the retina. (assignmentpoint.com)
Capsule7
- The lens has three main parts: the lens capsule, the lens epithelium, and the lens fibers. (wikipedia.org)
- The lens capsule is a relatively thick basement membrane forming the outermost layer of the lens. (wikipedia.org)
- Inside the capsule much thinner lens fibers form the bulk of the lens. (wikipedia.org)
- The lens capsule is a smooth, transparent basement membrane that completely surrounds the lens. (wikipedia.org)
- The capsule is very elastic and so allows the lens to assume a more spherical shape when the tension of the suspensory ligaments is reduced. (wikipedia.org)
- Attachment must be strong enough to stop the ligament being detached from the lens capsule. (wikipedia.org)
- Partial or complete opacity on or in the lens or capsule of one or both eyes, impairing vision or causing blindness. (lookformedical.com)
Retina2
- If the eyeball is too short or the lens too flat or inflexible, the light rays entering the eye - particularly those from nearby objects - will not be brought to a focus by the time they strike the retina. (assignmentpoint.com)
- If the eyeball is too long or the lens too spherical, the image of distant objects is brought to a focus in front of the retina and is out of focus again before the light strikes the retina. (assignmentpoint.com)
Cataract1
- Clear lens extraction causes a loss of accommodation but is preferred if the patient is older than 45 years or has any degree of cataract. (medscape.com)
Power1
- 2) Increasing the front curvature of the spectacles lens without changing the lens power. (examyear.com)
Shape5
- In many land animals the shape of the lens can be altered, effectively changing the focal length of the eye, enabling them to focus on objects at various distances. (wikipedia.org)
- Land vertebrate lenses usually have an ellipsoid, biconvex shape. (wikipedia.org)
- A human adult the lens is typically about 10mm in diameter and 4mm thick though changes shape with accommodation and size due to grow throughout a person's lifetime. (wikipedia.org)
- Unlike the lens on a camera, the lens of the eye is able to change its shape and thus serves to fine-tune the vision process. (assignmentpoint.com)
- These muscles relax and contract in order to change the shape of the lens. (assignmentpoint.com)
Structures1
- Anatomists will often refer to positions of structures in the lens by describing it like a globe of the world. (wikipedia.org)
Correct2
- Eyeglasses with convex lenses can correct the problem. (assignmentpoint.com)
- 16. With regard to spherical aberration, which statement is correct? (examyear.com)
Eyes4
- One critical a part of our eyes is called the crystalline lens. (daohangtiaozhuan.com)
- [5] The eyes of most cephalopods , fish , amphibians and snakes have fixed lens shapes, and focusing is achieved by telescoping the lens in a similar manner to that of a camera . (knowpia.com)
- Clear calcite crystals formed the lenses of their eyes. (knowpia.com)
- In contrast to compound eyes, simple eyes have a single lens. (knowpia.com)
Cells3
- By providing the lens fibers with nutrients and removing waste the cells of the epithelium regulate maintain lens homeostasis. (wikipedia.org)
- The cells of the lens epithelium also divide into new lens fibers at the lens equator. (wikipedia.org)
- A heterogeneous family of water-soluble structural proteins found in cells of the vertebrate lens. (lookformedical.com)
Image1
- The Artisan lens is shown in the image below. (medscape.com)
Point1
- The lens is 8.5 mm at the widest point, far away from the angle of the anterior chamber. (medscape.com)
Enter1
- Light which passes through the pupil opening, will enter the crystalline lens. (assignmentpoint.com)
Light1
- By 25 years of age the ability of the lens to alter the light path has reduced to 10 dioptres and accommodation continues to decline with age. (wikipedia.org)
Surface2
- En face OCT reflectance images which accompany OCTA studies offer a glimpse of the macrophage-like cellular activity above the retinal surface which responds to systemically instigated vascular events below. (stanford.edu)
- 2) Itis least in a plano - convex lens when the plane surface faces the object. (examyear.com)
Camera1
- Accommodation is analogous to the focusing of a photographic camera via changing its lenses. (wikipedia.org)
Similar1
- This suggests that the ICL geometry (spherical vs toric) is a factor with limited influence on the vault, thus the sizing method of a sICL and tICL should be similar. (biomedcentral.com)
Presence1
- The presence of these proteins accounts for the transparency of the lens. (lookformedical.com)
Maintain1
- Alpha-crystallins also act as molecular chaperones that bind to denatured proteins, keep them in solution and thereby maintain the translucency of the lens. (lookformedical.com)
Order1
- It is presumed to be synthesized by the lens epithelium and its main components in order of abundance are heparan sulfate proteoglycan (sulfated glycosaminoglycans (GAGs)), entactin, type IV collagen, laminin. (wikipedia.org)