Concave Lenses Are for the Nearsighted, Convex for the Farsighted. Concave lenses are used in eyeglasses that correct nearsightedness. Because the distance between the eye’s lens and retina in nearsighted people is longer than it should be, such people are unable to make out distant objects clearly.

Complex photographic lenses can consist of more than 15 lens elements. Most lens elements are made with curved surfaces with a spherical profile.

The front element is the one exposed to the scene when the photographic lens is mounted in the camera. It is the most visible (and vulnerable) element. It is the first element in the series of elements in the lens. It is the first to receive light entering the lens from the scene.

Glass is the most common material used to construct lens elements, due to its good optical properties and resistance to scratching. Other materials are also used, such as quartz glass, fluorite, plastics like acrylic (Plexiglass), and even germanium and meteoritic glass.

The predominant manufacturing process of plastic is injection molding. The basic process of injection molding is to melt the plastic resin so it can flow freely. This fluid is injected under high pressure to a precision mold cavity. The shape of the mold cavity determines the shape of the lens element.

A concave lens causes all rays to diverge. Concave lenses create only virtual images. After the rays are refracted, they never converge and so there will be no real images. All concave lens images will be upright, virtual, and diminished, and can be found between the F and the lens.

diverging lens

converging lens

A convex lens is thicker at the centre and thinner at the edges. A concave lens is thicker at the edges and thinner at the centre. Due to the converging rays, it is called a converging lens. Due to the diverging rays, it is called a diverging lens.

There are numerous uses of the concave lens, like in telescopes, cameras, lasers, glasses, binoculars, etc.

• Concave Lens Uses. SpectaclesLasersCamerasFlashlightsPeepholes.
• Concave lens used in glasses.
• Uses of concave lens in lasers.
• Use of concave lens in cameras.
• Used in flashlights.
• Concave lens used in peepholes.

Convex lens is used as

• It is used as Magnifying Glass.
• It is used to Make Microscope.
• It is used in spectacles to correct the vision. It cures defects called hypermetropia (far sightedness) where patients can’t see objects closer to them.

Lenses are used in various imaging devices like telescopes, binoculars and cameras. They are also used as visual aids in glasses to correct defects of vision such as myopia and hypermetropia.

Convex lenses are used in simple camera. Convex lenses are used in magnifying glass or magnifying lenses (by palmists, watchmakers etc). Convex lenses are used in making microscopes, telescopes and slide projectors.

Convex lenses are used to correct farsighted vision problems. Similarly, concave lenses are used to correct nearsightedness. Compound microscopes and telescopes use both convex and concave lenses….Applications Of Lens.

The two most common types of lenses are concave and convex lenses, which are illustrated below in Figure 1.

Light

1. A magnifying glass (called a hand lens in laboratory contexts) is a convex lens that is used to produce a magnified image of an object.
2. Magnifying glasses are also useful for reading details on maps and for reading the fine print on legal documents.

A lens has the valuable property of forming images of objects situated in front of it. Single lenses are used in eyeglasses, contact lenses, pocket magnifiers, projection condensers, signal lights, viewfinders, and on simple box cameras.

Lens, in anatomy, a nearly transparent biconvex structure suspended behind the iris of the eye, the sole function of which is to focus light rays onto the retina.

Are contact lenses safe? The latest innovations in eye technology make contact lenses extremely safe and as long as you follow a thorough eye care routine, you should encounter no problems at all. Most lenses are now made of silicone hydrogel which has allows a higher level of oxygen to reach the cornea.

Advantages: Wearing glasses reduces the need to touch eyes, which in turn reduces the likelihood of irritating eyes or developing an eye infection. Eyeglasses won’t exacerbate the problem if a person has dry or sensitive eyes. Eyeglasses generally are cheaper than contact lenses.

It is the second part of your eye, after the cornea, that helps to focus light and images on your retina. Because the lens is flexible and elastic, it can change its curved shape to focus on objects and people that are either nearby or at a distance. The lens provides 25-35% of your eye’s focusing power.

Humans have two eyes, but we only see one image. We use our eyes in synergy (together) to gather information about our surroundings. They show each eye a slightly different image. The two images show the objects as seen from slightly different angles, as would be when you saw the object in real life.

convex lens

Your eyes will lose the ability to move and focus on near objects, but they won’t change shape.

Eye Shape #1 – Almond Eyes Almond eyes are considered the most ideal eye shape because you can pretty much pull off any eyeshadow look.

Exophthalmos, also known as proptosis, is the medical term for bulging or protruding eyeballs. It can affect 1 or both eyes and is most often caused by thyroid eye disease.

Rubbing stimulates the eyes’ lacrimal glands, which creates lubrication and gives some relief. And there’s more than just the feeling of an itch vanquished, pressure on the eyes actually stimulates the vagus nerve. That reflex slows down your heart rate and can take you from tired to downright snoozing.

Rubbing is harmful to people with certain pre-existing eye conditions. Eye rubbing is particularly bad for a glaucoma patient with already heightened eye pressure. It can engender nerve damage and permanent vision loss.