I believe it can be used for any lens. Just be sure to use the correct sign. Check the "lensmaker's equation" in Wikipedia, and the comments about what sign to use.
A lens that only has one flat surface is called a plano convex lens. The plano convex lens makes fringes circular because the air film is symmetrical.
we need convex lens in eyes as convex lens bulges out and thus focuses the outside light rays at a particular point in our eye, so then only we are able to see.
Virtual image
You mean the entering rays into the convex lens is already in convergence mode. Ok. Now as it enters into the convex lens convergence would be increased as convex lens would do only converging phenomenon.
A convex lense forms only a virtual image.
Convex lens produces both real and virtual images. But concave lens produces only virtual images for real objects. If object is virtual then real image could be produced by a concave lens.
Lenses that can create a real image include converging lenses such as convex lenses. Lenses that can create a virtual image include diverging lenses such as concave lenses. The type of image formed depends on the focal length and the object distance from the lens.
It only works when it is open and it can only focus on one object at a time.
Only a convex lens forms any kind of real image and the size of the image is dependent upon the focal length (hence the curvature and and substance) of the lens. A concave lens forms a virtual or imaginary image in front of the lens. It is one that cannot be projected onto a surface. Perhaps what you mean has to do with convergence and divergence. A convex lens causes light rays to converge (come together at a point), while a concave lens causes rays to diverge.
Excellent question. The answer is actually yes! According to the lens makers formula, it will change based on the refractive index of the material of the concave mirror wrt the medium. Google Lens makers formula for better understanding! NO! the focal length of the mirror will not change if it would be a lens then the focal length would change. The lens maker's formula is for Lenses only!
No, any polygon.
The secret is that after refraction through convex lens if the refracted rays converge then it would form a REAL image and if the rays are diverging then it would form a VIRTUALimage.So, when the object is at or beyond the focus (F) of the convex lens then we have only converging refracted rays, hence real imageIf the object lies in between focus (F) and optical centre (O) of the lens, then refracted rays come out diverging and so only virtual images are formed.