SCI SECOND QUARTER LESSON 2 G10

LIGHT

Refraction

The change in the direction of light when it passes from one medium to another of different optical density, caused by the change in the speed of light at the boundary.

Optical Density

It refers to the transparency of a material to light. The higher the optical density of a material, the slower light travels through it.

Index of Refraction

A measure of how much light slows down as it passes through a medium. Higher optical density results in a higher index of refraction.

Spherical Lens

A piece of transparent material with at least one spherical surface. Spherical lenses can be convex or concave.

Convex Lens

A lens that is thicker at the middle than at the edges. It is used to converge light rays and can correct farsightedness.

Concave Lens

A lens that is thicker at the edges than at the middle. It diverges light rays and is used to correct nearsightedness.

Converging Lens

Lenses that bring light rays together, forming real or virtual images. Convex lenses are converging lenses.

Diverging Lens

Lenses that spread light rays apart, forming only virtual images. Concave lenses are diverging lenses.

Myopia

Nearsightedness, where a person can see nearby objects clearly but has difficulty seeing distant objects. Corrected with concave (diverging) lenses.

Hyperopia

Farsightedness, where a person can see distant objects clearly but has difficulty focusing on nearby objects. Corrected with convex (converging) lenses.

Presbyopia

Age-related vision problem where the eye loses its ability to focus on close objects due to the aging process.

Camera

A device used to capture permanent records of images, resembling the eye in function. It uses a lens to focus light onto a sensor or film.

Magnifying Glass

A converging lens that produces a virtual, upright, and enlarged image of an object placed closer than its focal length.

Microscope

An instrument used to observe small objects or microorganisms, consisting of at least two lenses: one eyepiece lens and one objective lens.

Light Microscope

A type of microscope that uses at least two convex lenses—one for the eyepiece and one for the objective lens.

Compound Microscope

A microscope that consists of both an objective lens and an eyepiece lens to magnify small objects.

Telescope

A device used to view distant objects. There are two types: refracting (uses lenses) and reflecting (uses mirrors).

Refracting Telescope

A telescope that uses lenses as the objective and eyepiece to focus light.

Reflecting Telescope

A telescope that uses a concave mirror as the objective to gather and focus light.