All flashcards
Flashcard 1: Which part of the eye focuses light onto the retina?
Answer: Lens. Bends light rays to create a clear image on the retina.
Flashcard 2: Which option best completes the idea: Light usually travels in lines.
Answer: Straight. Light rays don't bend without obstacles.
Flashcard 3: Choose the best reason a black shirt looks dark in sunlight.
Answer: It absorbs most light and reflects little to the eye. Dark colors are poor reflectors.
Flashcard 4: Which part of the eye receives incoming light and forms an image?
Answer: Retina. Light-sensitive layer at the back of the eye.
Flashcard 5: What must happen for you to see an object that does not make its own light?
Answer: Reflected light from the object must enter your eyes. Objects don't glow, so we see them by reflected light.
Flashcard 6: What is the definition of reflected light?
Answer: Light that bounces off a surface after hitting it. Light changes direction when it hits a surface.
Flashcard 7: What is the main role of the pupil in vision?
Answer: It controls how much light enters the eye. Opens wide in darkness, narrows in bright light.
Flashcard 8: Which part of the eye changes size to adjust the amount of light entering?
Answer: Iris. Colored muscle that makes the pupil larger or smaller.
Flashcard 9: What does it mean if an object is described as luminous?
Answer: It produces its own light. Examples include the sun, light bulbs, and fire.
Flashcard 10: What is the main job of the retina in vision?
Answer: It senses light and sends signals to the brain. Contains cells that detect light and create nerve signals.
Flashcard 11: Which option correctly describes how a nonluminous book is seen: emits light or reflects light?
Answer: Reflects light. Books don't glow; they need light to bounce off them.
Flashcard 12: What does it mean if an object is described as nonluminous?
Answer: It does not produce light and must reflect light to be seen. Most everyday objects are nonluminous.
Flashcard 13: What happens to vision if no light is reflected from an object into your eyes?
Answer: The object cannot be seen. No light reaching the eye means no visual signal.
Flashcard 14: Which situation makes an object easiest to see: more reflected light to the eye or less reflected light?
Answer: More reflected light to the eye. Brighter objects reflect more light to our eyes.
Flashcard 15: Choose the best reason a white shirt looks bright in sunlight.
Answer: It reflects most of the light that hits it. White surfaces are good reflectors of all light colors.
Flashcard 16: Identify what must be present to see an object in a completely dark room.
Answer: A light source so light can reflect into the eye. Without light, there's nothing to reflect.
Flashcard 17: Which option best explains why you can see the Moon at night?
Answer: It reflects sunlight into your eyes. The Moon doesn't make light but reflects the Sun's.
Flashcard 18: Identify the correct statement: Light travels from the eye to the object or from the object to the eye.
Answer: From the object to the eye. Eyes receive light; they don't send it out.
Flashcard 19: Which option best explains why a mirror lets you see your face?
Answer: It reflects light from your face into your eyes. Mirrors are smooth surfaces that reflect light well.
Flashcard 20: Identify the correct light path for seeing a chair: source → chair → eye or chair → source → eye.
Answer: Source → chair → eye. Light must hit the chair first, then bounce to your eye.
Flashcard 21: Choose the correct statement: Do most everyday objects emit light or reflect light?
Answer: Most everyday objects reflect light. Only special objects like bulbs produce light.
Flashcard 22: What happens to vision in a completely dark room with no light source?
Answer: Objects cannot be seen because no light reaches the eyes. Vision requires light to function.
Flashcard 23: Which surface reflects light more clearly: a smooth mirror or rough paper?
Answer: A smooth mirror. Smooth surfaces create organized reflections.
Flashcard 24: What is absorption of light?
Answer: When a material takes in light instead of reflecting it. Dark objects absorb more light than they reflect.
Flashcard 25: Which part of the eye detects incoming light and sends signals to the brain?
Answer: The retina. Light-sensitive tissue at the back of the eye.
Flashcard 26: What must happen for you to see a non-glowing object such as a book?
Answer: Light must reflect off the object and enter your eyes. Objects don't glow; we see them via reflected light.
Flashcard 27: What is reflected light?
Answer: Light that bounces off a surface instead of being absorbed. Light changes direction when hitting surfaces.
Flashcard 28: Identify the process: Light hits an object and then bounces into the eye.
Answer: Reflection. The bouncing of light enables vision.
Flashcard 29: Which term describes an object that produces its own light, such as the Sun or a lamp?
Answer: A light source. Objects that generate light, not just reflect it.
Flashcard 30: Identify what changes when you move a flashlight away from an object in a dark room.
Answer: Less light reflects into the eyes, so the object looks dimmer. Distance reduces light intensity reaching objects.