The light from the boat would first enter through the cornea, the first layer of the eye. The cornea helps the retina focus on the light by bending the light waves. Next, the iris would control the movement of the pupil. The iris helps determine how much light will enter the eye. If the boat’s lights are bright, the iris will make the pupil smaller. If the boat’s lights are dull, the iris will dilate the pupil. After the iris and the pupil is the lens, the focus of the eye. The lens will change shape to focus on the image. If an object is closer to the eye, the lens will become rounder, while if an object is farther from the eye, the lens will flatten. Since the boat will most likely be rather far from the eye, the lens will be flat. Next is the retina, which contains the photoreceptor cells. The photoreceptor cells are the innermost layer of cells after the ganglion cells and bipolar neurons. The receptor cells include rods and cones, which take the light and convert them to neural signals for the brain. They then have to send the neural signals back through the bipolar neurons and ganglion cells, the latter that will form the optic nerve with its axons and carry the neuron signals to the brain. After the brain receives the information from the visual cortex, the brain goes through parallel processing where it is able to take many visual perceptions and combine them into one, creating a visual environment.
The vibrations from the sound of the engine will funnel through our ear or pinna where they will travel through the ear canal. It will hit the eardrum, which will vibrate at the same rate as the sound. Other structures such as the hammer, anvil, and stirrup will also vibrate. The stirrup will hit the membrane covering the inner ear, also known as the oval window. The inner ear is the cochlea, a structure with fluid inside of it. When the oval window vibrates, the cochlea also vibrates, causing tiny hair cells on the basilar membrane, located in the cochlea, to also vibrate. When the hair cells vibrate, it causes the attached neurons to send neural signals through the auditory nerve to the thalamus. From the thalamus, the neural signals will reach the auditory cortex and become processed.