Pupils "constrict" when light enters, and "dilate "when the lighting dims
The part of the eye that dilates is known as the pupil. It sometimes dilates when you look at someone that you are physically attracted to. This happens because of a chemical reaction in your brain. Pupils also dilate according to how much light is present to allow better vision. Pupils are dilated when there is little light available. You can test this out by looking in a mirror where there is a lot of light (your pupils should be very small because allowing too much light in damages the eyes). Then look into a mirror where there is less light and your pupils will have dilated. During a concussion, a person may also have dilated pupils. I'm not sure why, but probably as a result due to the force of impact sustained by the head.
You probably mean the pupillary reflex. It is the reflex responsible for your pupils constricting (becoming smaller) when exposed to light and dilating (becoming bigger) when you walk into a dark room.
They both examine pupils (It's a joke Joice).
The crystalline lens is the part of the eye that bends/refracts the light rays as it passes through it.
When a ray of light is reflected off a mirror and into a glass of water, it undergoes both reflection and refraction. The light ray bounces off the mirror's surface and then bends as it enters the water due to the change in the medium's density. This causes the light ray to change direction and speed as it travels through the water.
A light is an open system. It runs on electricity, which enters the light from outside, and it emits light, which leaves. Energy is both entering and leaving the system all the time (at least, when the light is on).
The constriction of pupils in response to bright light is called the pupillary light reflex. If the light is shining directly into one eye, then the pupil in that eye will constrict (a direct response), but so will the pupil in the non-illuminated eye (a consensual response).This reflex involves two cranial nerves: the optic nerve, which senses the light, and the oculomotor nerve, which constricts both pupils. It is considered involuntary since you don't think about it.
It is either transmitted or reflected. Often, different portions of the light do both.
When the light ray strikes the surface of the prism, both when it enters and when it leaves, it bends owing to the different in the speeds of light in air and the material of which the prism is made. The amount of bending depends in part on the frequency of the light which is related to the colour of the light, hence the appearance of a colour spectrum which can be seen from a triangular prism.
Both focus light
When light is shone into one eye, the pupillary light reflex causes both pupils to constrict simultaneously due to the connection between the two eyes. This is known as a consensual response and helps to regulate the amount of light entering both eyes.
Conjunctiva is the name of a thin layer that lines the cornea and continues to surround the inside of both the upper and lower eyelid. Conjunctivitis is inflammation of the conjunctiva and this distorts the light that enters the eye. It would be comparable to looking through frosted glass.