**3.1 Complexity of visual functioning**

Increased knowledge in neurology, anatomy, and psychology has provided new insight into the complexity of the visual sense (e.g., [16–21]). It is evident that visual functions such as a clear VA at near and far for seeing details and object together with the ability of noticing people, objects, and movements in the VF are essential for being able to function in our surroundings. A single image on different distances is reached with a functional vergence-convergence where the eyes stay parallel when looking at a point far away and turns more and more inward, converge, when fixating an object that comes closer. At the same time, the eye lenses must change their form, accommodate, for bending the light waves to fall on the central part of the retina. Only then the image is seen clearly respective to the distance. This accommodation function can be compared with a lens in a camera which also has to change its form due to the distance for the focused object. Convergence and accommodation are closely connected and must function coordinated and easily when the eyes are tracking and scanning on different items and objects of interest at far or near. These

functions are developing throughout childhood in response to stimulation and activation. This development is going on until children are in their teens [22].

Researchers have shown how cognition can influence vision by selectively directing the gaze to special elements of interest [23], but first of all, vision provides us with information about the world around us. Intact visual inputs are, among other things, a prerequisite for motor activities, higher level visual abilities, and the cognitive development. Clear visual inputs are necessary for fundamental visual perceptual skills, that is, identification of objects and people and for concepts of same—different, comparing, sorting, matching, catching, reading, and writing.

#### **3.2 Visual development and stimulation**

In order to support the development of vision, children need an environment and activities which stimulate their senses, including their visual sense, from an early age on. Visual capacity is often taken for granted, although as we pointed out, it develops through childhood and also during the years in primary school. Children should be engaged in visual activities together with their caretakers and teachers from a very early age on. Words should accompany objects and pictures. When pointing to pictures shifting from close or far, the child is training accommodation and convergence, steady fixation, and saccades (the gaze jump from one position to the next) together with eye-hand coordination. This can be strengthened by entering a dialog of sounds and words, pointing to interesting features of pictures, comparing and naming objects of different sizes and perspectives, and imitating sounds of animals or cars. Making reading with children as part of a routine is a reciprocal and bonding experience between children and their caretakers [24]. Such activities can be the inspiration for children to draw or do other eye-hand activities.

Children should be encouraged to "look" at elements in their environment and become aware of their surroundings, of the natural and man-made environments, of differences between things they encounter such as flowers, plants, animals, colors, objects, shapes, etc. Teachers should have conversations with children about what they see and stimulate their visual perception, visual discrimination, and visual memory in different ways through games and structured exercises with a variety of age-appropriate materials. Especially, preschool teachers can include a number of activities that are stimulating and supportive of the visual system based on the abilities of the child. Puzzles, memory games, and building with blocks with and without models can give a good foundation for visual development. Children should do activities that stimulate their near and distance vision: They should be involved in coloring with crayons at near but should also play ball with friends from a distance. During the past years, more emphasis worldwide has been put on "digital learning" and the use of computers and tablets in preschools and schools. Although digital media can be used successfully in many different areas of life, there are reasons for caution of their increased use, particularly in preschools. Interestingly, many executives of technology development in Silicon Valley, one of the main centers of global digital development in the United States, seem to want to educate their children in a "device-free" school program, such as the Waldorf Schools [25]. As experts in technology development, they also seem to know the limits and even dangers of their products on child development. In addition, more and more children and students turn myopic because of all the near work done on screens [26].

Children need direct interaction with the material world to develop concepts. They need to touch, see, smell, grasp, and reach for real objects and have real experiences in the world surrounding them. Only then can they develop crucial vision, visual attention, and visual motor skills. If they have a firm grasp on

those more concrete experiences, they can move on to more abstract visual concepts such as letters and numbers.
