Physics

Article about the Equation of loupe magnifying glass

As explained in the topic loupe (magnifying glass), an object appears small when viewed from a great distance and looks great when viewed at close range. The difference in the size of the object seen by the eye is caused by the difference in angle between the eye and the object. When an object is very far away from the eye, the angle between the eye and the object is smaller so that the image formed on the retina of the eye is also smaller. Conversely, when the object is close to the eye, the angle between the eye and the object is larger so that the image formed on the retina of the eye is also more significant. The closer to the eye, the higher the angle between the eye and the object, so that the image that forms on the retina is also getting bigger. Kindly note that the average human eye has a near point is 25 cm so that the distance between the eye and the object cannot be smaller than 25 cm. It can be concluded that the angle between the normal eye of an average human and an object is maximum when the distance between the eye and the object is 25 cm.

Read more

Definition of Loupe magnifying glass

A loupe or magnifying glass is a convex lens that is used to help the eye see an object that is difficult to observe directly using the eye. The loupe is called a simple magnifier because it has limited ability to magnifying the image of an object. In the next lesson, you will learn about non-simple magnifiers such as microscopes, etc.

Read more

Article about Contact lens Farsightedness Nearsightedness

Nearsightedness eyes can be normalized using eyeglass lenses and contact lenses. Eyeglass lenses are affixed to the eyeglass, while contact lenses are attached to the eyeball. Eyeglass has a certain distance from the eye, while contact lenses stick to the eye so that the distance between the contact lens and the eye can be ignored.

An example of problems experienced by a person with nearsightedness and farsightedness is explained, what types of lenses are used to normalize the eyes, what is the focal length and power of the lens. This focuses on the use of contact lenses in normalizing nearsightedness and farsightedness.

Read more

Article about Eyeglass Farsightedness Nearsightedness

Nearsightedness can be normalized using eyeglass lenses and contact lenses. Eyeglass lenses are affixed to the eyeglass, while contact lenses are attached to the eyeball. Eyeglass has a certain distance from the eye while the contact lenses stick to the eye so that the distance between the contact lens and the eye can be ignored.

In this paper, we explain examples of problems experienced by sufferers of nearsightedness and farsightedness, the type of lens used to normalize the eye, and the focal length and the power of the lens. This focuses on the use of glasses to normalize nearsightedness and farsightedness.

Read more

Definition of the nearsightedness eye

Nearsightedness or hyperopia is an optical eye abnormality in which the eye cannot see the near point or the near point looks blurred. The average normal-eyed human has a near point of 25 cm.

The cause of the nearsightedness eye

Based on the previous explanation, it can be concluded that the cause of farsightedness is the cornea and the lens of the eye is less curved,

so that the focal length of the cornea-eye lens system is more significant, causing the beam of light from the near point to be focused behind the retina.

Read more

Definition of the farsighted eye

Nearsightedness or hyperopia is an optical eye abnormality in which the eye cannot see a near point clearly, or the near point looks blurred. Although it is difficult to observe a near point, people with nearsightedness can see the far point. The near point is the closest distance that can be seen by the normal eye. The average normal-eye has a point near 25 cm. The far point is the farthest distance that can be seen by normal eyes. The average normal-eye person has an infinite point. Infinite is a term used to describe the length of a very distant object.

Read more

Article Optical instrument human eye

Parts of the eye

The cornea is a transparent, hard membrane covering the front of the eye. The cornea refracts the beam of light entering the eye.

The pupil is black parts of the eye. The pupil is black, therefore absorb almost all the light. A pupil is a hole through which light passes into the eye. The larger the diameter of the pupil, the more light enters the eye and the smaller the size of the pupil, the less light comes to the eye.

The iris controls the size of the pupil. When the environment around the eye is very bright, the iris minimizes the pupil. Conversely, when the environment around the eyes is less bright, the iris enlarges the pupil so that the amount of light entering the eye is large. If you have observed the difference between the cat’s eye during the day and night, then you can easily understand the function of the iris.

Read more

The object distance is smaller than the focal length of the convex lens (do < f)

Based on the calculation of the image formation by the convex lens, it can be concluded that the object distance (do) is smaller than the focal length (f) of the convex lens, the image properties are:

– Virtual means the beam of light does not pass through the image

– Upright

– The farther the object is from the convex lens, the greater the image size

– The farther the object is from the convex lens, the image farther away from the convex lens

Read more

Article about Equation of converging (convex) lens

Before learning the equation of the convex lens, understand the sign rules of the convex lens below.

Sign rules of the convex lens

– The object distance (do)

If an object is passed through a beam of light, then the object distance is positive.

– The image distance (di)

If the beam of light passes the image, then the image distance is positive (real image). If the beam of light does not pass through the image, the image distance is negative (virtual image).

Read more

Article about Image formation by converging (convex) lens

To understand the image formation by the convex lens, learn example problems and solution below. In this case, the object is assumed to be at a certain distance from the convex lens,

then draw the image formation by the convex lens, the image distance from the convex lens and the magnification of the image by the convex lens.

The convex lens has a focal length of 20 cm. Objects with a height of 10 cm are located to the left of the lens. Determine the image distance, the magnification of the image and the image height, if:

Read more