FOOD STIMULI AND GENDER

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2.2 Eye Movements, Attention, and Preference
A brief description of the human eye and its movements is offered for a better
understanding of the eye-tracking technology used in the present study.

2.2.1 The Human Eye
The human eyeball is divided into three layers:
1. An outer layer called the fibrous tunic consists of the sclera (the “white” part)
and cornea (transparent and curved).
2.

A middle layer named the vascular tunic is composed of the ciliary body,
choroid, and iris. The iris is a colored circle with a hole in the center, known as
the pupil, where light enters the eyeball (see figure 4).

3. The inner layer known as the retina gives the starting point of the visual path and
is divided into the pigmented and neural layers. The neural layer consists of three
layers: the photoreceptor, bipolar cell, and ganglion cell layers (Tortora &
Derrickson, 2010).