The Human Eye and the Colourful World Mind Map

Accommodation is the ability of the eye lens to change its curvature so that objects at different distances are seen clearly.

In answers, mention ciliary muscles, lens curvature, and focal length change together. That combination earns full concept credit.

The near point is the nearest distance at which an object can be seen clearly without strain.

Remember the standard near point of a normal adult eye as 25 cm unless the question states otherwise.

Myopia is a defect in which a person sees nearby objects clearly but distant objects appear blurred.

In correction answers, mention concave lens, diverging rays, and image shifting to the retina.

Hypermetropia is a defect in which a person sees distant objects clearly but nearby objects appear blurred.

For hypermetropia, always mention behind the retina and the use of a convex lens.

Presbyopia is an age-related defect in which the power of accommodation decreases and near vision becomes difficult.

Mention age, reduced accommodation, and the shifting near point when you answer presbyopia questions.

Dispersion is the splitting of white light into its constituent colors when it passes through a prism or similar transparent medium.

In board answers, mention unequal deviation of colors and the order red to violet.

A rainbow is a natural spectrum of sunlight seen in the sky after dispersion, refraction, and internal reflection in water droplets.

In a 3-mark answer, mention refraction, dispersion, and internal reflection in water droplets.

Atmospheric refraction is the bending of light by layers of air in the Earth's atmosphere because the air density changes with height.

When explaining sunrise or sunset effects, mention that the atmosphere bends light toward denser air layers.

Scattering is the redirection of light in many directions when light hits tiny particles in a medium.

For a strong answer, mention that shorter wavelengths scatter more and connect it to sky color.

The Tyndall effect is the scattering of light by colloidal particles, making the path of a light beam visible.

In exam answers, mention colloidal particles and the visible beam path. That is the core idea.