Untitled Quiz

Study Notes

Myopia (Near-sightedness): A condition where distant objects are blurred, while nearby objects are clear, due to the far point being closer than infinity.
Hypermetropia (Far-sightedness): A condition where distant objects are clear, but nearby objects are blurred, resulting in a near point further away than the typical 25 cm.
Presbyopia: An age-related condition where the eye's accommodation ability decreases, making it difficult to focus on near objects.

Caused by a long focal length of the eye lens or a smaller eyeball size.
Nearby images are focused behind the retina, requiring objects to be placed beyond 25 cm for clear vision.
Corrected using convex lenses to converge light rays onto the retina.

Occurs due to the weakening of ciliary muscles and reduced flexibility of the eye lens with age.
Near point gradually increases, affecting the ability to see close objects clearly.
Often requires bifocal lenses that combine concave (for distance) and convex (for near) corrections.

Eyeglasses: Utilize spherical lenses (concave for myopia, convex for hypermetropia) for vision correction.
Contact lenses: Provide alternative vision correction directly on the eye's surface.
Surgical interventions: Offer permanent solutions for refractive defects.

Power of accommodation: The eye's ability to adjust focal length for focusing on objects at varying distances.
Near point: Closest distance for clear vision, approximately 25 cm for young adults.
Far point: Distant limit, ideally infinity for normal vision.

Light rays change direction as they pass through different mediums (like air to glass), resulting in refraction.
Triangular prisms bend light, leading to an angle of deviation when light exits.

Tyndall effect: Scattering of light by particles in a medium, visible in smoke or mist.
The blue sky is a result of shorter wavelength light (blue) scattering more effectively than longer wavelengths like red.
Red light's ineffectiveness at scattering allows it to be prominent during foggy conditions.

Stars twinkle due to atmospheric disturbances affecting light paths, while planets do not twinkle because they have a more stable view.
In high altitudes, light scattering is minimal, resulting in a darker sky.
Eye donations after death can provide vision for the blind, reflecting the importance of eye health.