PRASHANT KIRAD
Human eye And The Colorful World
Near point: Minimum distance for clear vision without strain,
Sense organ for vision, located in the
typically 25 cm for a normal eye.
eye sockets of the skull; it helps us
see by detecting light and colors. When looking at a nearby object, the ciliary muscles contract,
making the lens thicker and decreasing its focal length.
Aqueous Humor: Clear fluid
between cornea and lens; Far point: Maximum distance seen clearly, normally at infinity.
maintains eye pressure and When looking at a distant object, the ciliary muscles relax,
nourishes cornea and lens. making the lens thin and increasing its focal length.
Pupil: Small opening in the iris;
controls light entry into the eye Defects of Vision & their Correlation
Iris: Ring-like, muscular tissue behind the cornea; determines
eye color and adjusts pupil size.
Lens: Fibrous, jelly-like, convex; focuses light on the retina,
creating a real, inverted image.
Cornea: Outermost transparent part; provides most light
refraction
Ciliary Muscles: Hold and adjust the lens curvature for focus.
Retina: Delicate membrane with light-sensitive cells.
Rods: Detect light intensity.
Cones: Detect primary colors cataract
Vitreous Humor: Provides nutrients and maintains eye shape.
Optic Nerve: Transmits visual information from the retina to cloudy or
the brain. blurry vision
Sclera: Tough, white outer covering of the eye; provides
protection.
Causes: age related
Power of Accommodation condition, weakening
The ability of the human eye to focus on objects at different of eye muscles
distances by changing the focal length of the eye lens,
controlled by ciliary muscles.
treatment: surgery.
Defects of Vision & their Corrections Dispersion of White Light: Splitting of white light into
1. Myopia (Nearsightedness) seven colors when passing through a prism.
Cause: The eyeball is too long or the cornea is too curved, causing light to Spectrum: The band of seven colors formed.
focus in front of the retina.
Effect: Distant objects appear blurry, while close objects are clear.
Color Sequence: VIBGYOR (Violet, Indigo, Blue, Green,
Correction: Concave (diverging) lenses spread out light rays so they focus Yellow, Orange, Red).
on the retina. Causes:
2. Hyperopia (Farsightedness) Varying refraction indices of different colours.
Cause: The eyeball is too short or the cornea is too flat, causing light to
focus behind the retina.
wavelength of light when passing through transparent
Effect: Close objects appear blurry, while distant objects are clear. medium like prism.
Correction: Convex (converging) lenses bend light to focus it correctly on Newton’s Experiment: Used a
the retina.
3. Astigmatism
second inverted prism to
Cause: The cornea or lens has an irregular shape, leading to multiple recombine the spectrum into
focus points. white light, proving sunlight is
Effect: Blurred or distorted vision at all distances. made up of seven colors.
Correction: Cylindrical lenses or toric contact lenses adjust for the uneven
curvature.
White Light: Any light
4. Presbyopia producing a similar spectrum
Cause: Aging causes the lens to lose flexibility, making it harder to focus to sunlight is called white
on close objects.
light.
Effect: Difficulty reading or seeing nearby objects.
Correction: Bifocal or progressive lenses, and reading glasses. Red is the least deviated colour as it has largest/longest
Advantages of having eyes in front of the face... wavelength.
Violet is the most deviated colour as it has smallest
Gives a wider field of view.
wavelength in visible spectrum.
Enhances the ability to detect faint objects.
Provides three dimensional view. Natural spectrum: Rainbow :
Refraction through a glass prism Refraction of Sunlight -- Dispersion into Colors -- Internal
Prism: Transparent refracting Reflection -- Refraction Again
medium. Structure: Two
triangular bases, three Rainbow: A natural spectrum
rectangular lateral surfaces. appearing in the sky after a
Angle of Prism: Angle rain shower, caused by the
between two lateral faces. dispersion of sunlight by tiny
Angle of Deviation: Angle water droplets in the
between incident and atmosphere.
emergent rays.
Human eye And The Colorful World
Near point: Minimum distance for clear vision without strain,
Sense organ for vision, located in the
typically 25 cm for a normal eye.
eye sockets of the skull; it helps us
see by detecting light and colors. When looking at a nearby object, the ciliary muscles contract,
making the lens thicker and decreasing its focal length.
Aqueous Humor: Clear fluid
between cornea and lens; Far point: Maximum distance seen clearly, normally at infinity.
maintains eye pressure and When looking at a distant object, the ciliary muscles relax,
nourishes cornea and lens. making the lens thin and increasing its focal length.
Pupil: Small opening in the iris;
controls light entry into the eye Defects of Vision & their Correlation
Iris: Ring-like, muscular tissue behind the cornea; determines
eye color and adjusts pupil size.
Lens: Fibrous, jelly-like, convex; focuses light on the retina,
creating a real, inverted image.
Cornea: Outermost transparent part; provides most light
refraction
Ciliary Muscles: Hold and adjust the lens curvature for focus.
Retina: Delicate membrane with light-sensitive cells.
Rods: Detect light intensity.
Cones: Detect primary colors cataract
Vitreous Humor: Provides nutrients and maintains eye shape.
Optic Nerve: Transmits visual information from the retina to cloudy or
the brain. blurry vision
Sclera: Tough, white outer covering of the eye; provides
protection.
Causes: age related
Power of Accommodation condition, weakening
The ability of the human eye to focus on objects at different of eye muscles
distances by changing the focal length of the eye lens,
controlled by ciliary muscles.
treatment: surgery.
Defects of Vision & their Corrections Dispersion of White Light: Splitting of white light into
1. Myopia (Nearsightedness) seven colors when passing through a prism.
Cause: The eyeball is too long or the cornea is too curved, causing light to Spectrum: The band of seven colors formed.
focus in front of the retina.
Effect: Distant objects appear blurry, while close objects are clear.
Color Sequence: VIBGYOR (Violet, Indigo, Blue, Green,
Correction: Concave (diverging) lenses spread out light rays so they focus Yellow, Orange, Red).
on the retina. Causes:
2. Hyperopia (Farsightedness) Varying refraction indices of different colours.
Cause: The eyeball is too short or the cornea is too flat, causing light to
focus behind the retina.
wavelength of light when passing through transparent
Effect: Close objects appear blurry, while distant objects are clear. medium like prism.
Correction: Convex (converging) lenses bend light to focus it correctly on Newton’s Experiment: Used a
the retina.
3. Astigmatism
second inverted prism to
Cause: The cornea or lens has an irregular shape, leading to multiple recombine the spectrum into
focus points. white light, proving sunlight is
Effect: Blurred or distorted vision at all distances. made up of seven colors.
Correction: Cylindrical lenses or toric contact lenses adjust for the uneven
curvature.
White Light: Any light
4. Presbyopia producing a similar spectrum
Cause: Aging causes the lens to lose flexibility, making it harder to focus to sunlight is called white
on close objects.
light.
Effect: Difficulty reading or seeing nearby objects.
Correction: Bifocal or progressive lenses, and reading glasses. Red is the least deviated colour as it has largest/longest
Advantages of having eyes in front of the face... wavelength.
Violet is the most deviated colour as it has smallest
Gives a wider field of view.
wavelength in visible spectrum.
Enhances the ability to detect faint objects.
Provides three dimensional view. Natural spectrum: Rainbow :
Refraction through a glass prism Refraction of Sunlight -- Dispersion into Colors -- Internal
Prism: Transparent refracting Reflection -- Refraction Again
medium. Structure: Two
triangular bases, three Rainbow: A natural spectrum
rectangular lateral surfaces. appearing in the sky after a
Angle of Prism: Angle rain shower, caused by the
between two lateral faces. dispersion of sunlight by tiny
Angle of Deviation: Angle water droplets in the
between incident and atmosphere.
emergent rays.
