How do we see with our eyes

Lesson 2 discussed the formation of images by plane mirrors. In Lesson 2, it was emphasized the image location is the location where reflected light appears to diverge from. For plane mirrors, virtual images are formed. Light does not actually pass through the virtual image location; it only appears to an observer as though the light is emanating from the virtual image location. In this lesson we will begin to see that concave mirrors are capable of producing real images (as well as virtual images). When a real image is formed, it still appears to an observer as though light is diverging from the real image location. Only in the case of a real image, light is actually passing through the image location.

If the light bulb is located at a different location, the same principles apply. The image location is the location where reflected light appears to diverge from. By determining the path that light from the bulb takes after reflecting from the mirror, the image location can be identified. The diagram below depicts this concept.

Orderinwhichlightpasses throughthe eye

No, animals do not emit light from their eyes to see in the dark. However, some animals have evolved to have highly sensitive eyes that can detect very low levels of light, allowing them to see in dark conditions. Additionally, some animals, like certain species of fish and insects, can produce bioluminescence, but this light is not used for vision in the same way as the misconception suggests.

The eye perceives images by capturing light that reflects off objects and enters the eye through the cornea and lens. This light is then focused onto the retina, where photoreceptor cells convert it into electrical signals that are sent to the brain for processing and interpretation.

Lightreflectioneyeproblem

Light travels in straight lines from a light source, reflects off surfaces, and enters the eye through the cornea. It then passes through the aqueous humor, lens, and vitreous humor before reaching the retina. The retina's photoreceptor cells (rods and cones) detect the light and convert it into electrical signals, which are transmitted to the brain via the optic nerve.

No, light does not travel from the eye to the object. Instead, light reflects off objects and then enters the eye, allowing us to see them. The eye functions as a receiver of light rather than a transmitter.

Howdoes the eyework simple explanation

Suppose that a light bulb is placed in front of a concave mirror at a location somewhere behind the center of curvature (C). The light bulb will emit light in a variety of directions, some of which will strike the mirror. Each individual ray of light that strikes the mirror will reflect according to the law of reflection. Upon reflecting, the light will converge at a point. At the point where the light from the object converges, a replica, likeness or reproduction of the actual object is created. This replica is known as the image. Once the reflected light rays reach the image location, they begin to diverge. The point where all the reflected light rays converge is known as the image point. Not only is it the point where light rays converge, it is also the point where reflected light rays appear to an observer to be diverging from. Regardless of the observer's location, the observer will see a ray of light passing through the real image location. To view the image, the observer must line her sight up with the image location in order to see the image via the reflected light ray. The diagram below depicts several rays from the object reflecting from the mirror and converging at the image location. The reflected light rays then begin to diverge, with each one being capable of assisting an individual in viewing the image of the object.

In ancient times, some philosophers, such as Pythagoras and later proponents of the emission theory of vision, believed that vision involved rays emanating from the eyes to the object. This misconception was eventually corrected by the work of scientists like Ibn al-Haytham (Alhazen) and Johannes Kepler, who demonstrated that vision results from light entering the eye.

You might notice that while the same principle applies for determining the image location, a different result is obtained. When the object is located beyond the center of curvature (C), the image is located between the center of curvature (C) and the focal point (F). On the other hand, when the object is located between the center of curvature (C) and the focal point (F), the image is located beyond the center of curvature (C). Unlike plane mirrors, the object distance is not necessarily equal to the image distance. The actual relationship between object distance and image distance is dependent upon the location of the object. These ideas will be discussed in more detail later in this lesson.