**8. Female gender and food security in sub-Saharan**

#### **8.1 Women and crop production**

Smallholder farmers produce 80% of agricultural production in sub-Saharan Africa [36, 37]. In subsistence farming, as practised in Africa, women are the primary sources of food production and little from men is necessary [37–41]. Sub-Saharan African women have the highest average agricultural labour force participation rate in the world, at 62.5% in 2012, compared with 36.4% globally. In Ghana, for instance, women produce 70% of the country's food crops, offer 52% of the agricultural labour force, provide 85% of the labour for agro-processing operations and 86% for food supply. Women made up 43.8% of the economically active population in sub-Saharan Africa as a whole in 2010, and 65% of those women worked in agriculture, with women delivering 70% of farm labour in Kenya [9, 42]. The importance of female agricultural workers in the world is unparalleled, even though life for rural women is not easy. Women do not have the same rights as men and must often balance domestic duties with agricultural work, such as sowing, weeding, harvesting and collecting firewood and water. Additionally, it can be more difficult for women to produce as much as men do in the farm setting, due to poor access to land, agricultural extension services and technologies.

#### **8.2 Women and livestock farming in SSA**

In less developing countries such as SSA, women generally can rear small animal husbandry (poultry, sheep, etc.), but men take care of the big head. As relayed by [43, 44], women are seen as key stakeholders in backyard poultry farming systems, and successful engagement in this sector requires gender-appropriate methods. Research has proven that women's poultry farming initiatives are more likely to lead to successful nutritional outcomes [33, 45–50]. In fact, the Food and Agriculture Organization enhances that increasing the productive resources available to women would reduce the number of hungry people in the world by about 12–17% [51]. Furthermore, it is undeniable that women play a fundamental role in food and nutrition protection at all food chain stages [52].

#### **8.3 Women and food transformation in SSA**

African women's involvement in every stage of the food system is crucial [53]. In SSA, most of the food processing infrastructures are traditional and women once

again are the key point of such a system of food processing. They are present from production, to distribution and nutrition. In fact, based on traditional knowledge, rural women process food and pass this knowledge to the next generation through their daughters. It is rare to have a modern infrastructure for food processing in urban or rural areas. Most modern processed foods are imported. And for the rare locally modern processed food, the price is high for the local market; as result, a large number of citizens cannot afford it. Therefore, it opts for foreign markets. In such decor, the only possibility which remains for these regions is to empower local actors like women with knowledge to create healthy and wholesome foods. So, then they could supply the market with the appropriate dishes fitting their social reality [52, 53].

As noticed, previously and with the current food insecurity situation in the underdeveloped world and peculiarly in SSA, empowering women is still the most suitable way for a rapid effective sustainable food security promotion.


**3.3 Debulking**

Debulking (or deep curettage) is considered a surgical procedure and it is often used in thicker lesions, reducing as much as possible the total volume. This procedure is usually performed either immediately or a few weeks before PDT [15, 23].

Even though it is considered a more invasive procedure compared with the simple curettage, it can be applied without anesthesia. The cosmetic outcome is considered favorable [23] and allows a significant reduction of the BCC thickness, which makes nodular lesions more responsive to the treatment [24, 25].

Whereas the topical PDT efficiency is about 72% when a previous debulking lesion is not applied, for debulked lesions this efficiency can increase up to 92% [23, 26]. Therefore, the debulking associated with PDT is a relevant option for multiple, pigmented, and nodular lesions, improving clinical response [27].

#### **3.4 Ablative fractional laser**

This technique consists of using a laser source to create ablated channels on the lesion surface, vaporizing a small portion of the tissue [28]. Usually, lasers with excitation wavelengths in far-infrared spectrum are used, due to the high absorption by the water in the tissue [29, 30]. The main types used are CO2-laser (10,600 nm), Er:YAG-laser (Erbium yttrium aluminum garnet, 2940 nm), and Er:YSSG-laser (Yttrium scandium gallium garnet, 2790 nm) [13].

The depth of the microchannels created varies according to the laser energy. The energies between 32 mJ and 380 mJ generate microchannels with a depth between 300 μm and 2100 μm [31]. Due to the increased skin penetration, this procedure makes PpIX fluorescence both more intense and homogeneous in deeper skin regions, and this can be controlled by adequately adjusting laser energy density [32, 33].

Studies using CO2 laser associated with PDT for lesions treatments showed an increase of about 20% in the clearance of different protocols comparing the treatment without and with the use of laser, respectively [34–36]. Although it is a reliable and effective method, it is also a more invasive procedure with a high potential for skin damage with scarring, discoloration, and even infection. Besides that, the costs of the devices are considered high compared with the abovementioned techniques [37].

#### **3.5 Microneedles**

Needles and especially microneedles (MNs) have been used as a method to enhance drug permeation through SC [38]. MNs have the advantages of being minimally invasive, its application is simple, well accepted by the patients, and it is cost-effective [39]. MNs have been developed with lengths up to 900 μm to avoid penetrating in vascular and nervous regions. Therefore, MNs can penetrate the SC without stimulating pain receptors, which is another advantage [40].

The MNs size cannot be seen by patients, thus reducing possible needle phobia. MNs have strong mechanical properties to enable disruption and penetration through the SC, reaching successfully the deeper skin layers without causing any bleeding due to the small length of needles [13].

There are MNs with different shapes (tetrahedron, pyramidal, conical, beveled tip, or tapered cone) that promote different insertion pathways and permeation into the skin. They also can be divided according to the material, such as solid (metallic) or polymeric (hydrogel or dissolving) types, and can be assembled either as a roller or as low-cost patches. The MNs can also be produced with a drug coating on their surface, to facilitate delivery, or hollow, to promote the delivery through channels [13]. The use of MNs rollers for enhancing penetration of topical cosmeceuticals has been well described and transdermal patches can be used easily by anyone [13, 39].

Some studies described a higher formation of PpIX in deeper skin regions when MNs are used and compared with topical application in animal models [41, 42]. A

recent paper by Requena *et al.* explored dissolving MNs containing ALA. The PpIX fluorescence intensity showed to be 5-times higher at 0.5 mm on average compared with cream in *in vivo* tumor mice model [43].

Solid MNs have been commonly used for skin pretreatment before conventional PDT, promoting a good PDT response for actinic keratosis [39]. However, their use for the treatment of BCC or squamous cell carcinoma SCC has not been investigated yet [13].


**Abstract**

This chapter adopts an integrative literature review to describe and analyze theories and empirical research on visual development, impairment, screening, and intervention. The purpose is to inform teachers on how to influence students' education and social growth through understanding vision. Vision is especially essential for reading, accessing classroom materials, and learning. Yet, in many countries, vision problems in children are not assessed and thus not treated. The negative consequences for individuals and society are often significant. Though there is an abundance of eye health specialists in developed countries, not all visual problems that influence learning and reading are screened or treated effectively. This is worse in developing countries where eye health infrastructure often is lacking. Even screening and treatment given through the eye healthcare system is not always sustainable, since regular follow-up is lacking. The literature review shows that vision is a developing sense important for learning and that teachers can screen children's vision and support visual development. It can be concluded that every child in the twenty-first century school should have teachers with knowledge in vision. An example of a higher education initiative is presented to illustrate possible further education for teachers in the area of vision.

**Keywords:** visual development, stimulation, learning through vision, vision screening, teacher education

## **1. Introduction**

The world is changing rapidly, and the necessity for good functional vision is greater than ever. Education is essential for the individuals' overall life quality and for personal, social, and occupational development. Societies depend on it for economic growth and democracy. Recent research revealed how important good vision is in all learning- and for all academic-related tasks. In classrooms around the world, visual inputs are involved up to 70% of the time [1], so even tiny disturbances can result in a lack of important information.

Unfortunately, not much has changed since Rogers, in 1924, claimed that the importance of vision in reading and writing is often overlooked [2, 3]. Even today few teachers have any special knowledge about the visual functions and vision disturbances [4] or how they affect learning, the development of motor skills and cognitive capacities. Reading is a particularly significant vision task depending on good visual acuity (VA) for detecting all the tiny details in a text. In addition,

it relies upon an intact functional visual attention span in the visual field (VF) for getting an overview of the next letters, the words to come, the end of line, and from where to continue reading the next text line. Vision is not a passive sensory system that is only receiving inputs; it is also an active and complex motor system that is continuously moving. The eyes must coordinate to fixate on the same spot, move around to different areas for searching, while the lenses adjust to the ever-changing locations. The goal is to give the brain clear inputs, no matter the distance. During reading, the gaze must jump precisely and should be coordinated from one fixation point to the next and adjust to the light level of the actual surrounding. This complexity indicates why vision must be considered in teaching [5–7]. There is no doubt that literacy is the foundation of almost all education and probably the most important skill to have in the twenty-first century, and this skill starts as a visual process. Thus, when children have problems with their vision, they may not be able to succeed in school [8].

Visual impairment is classified extensively by the International Classification of Diseases, ICD-11 [9]. Although the criteria are health classifications, many countries use them very strictly as eligibility criteria for educational services by the teacher for the visually impaired or blind. In most cases, only a significantly reduced VA and/or a VF loss after correction of refractive error will lead to services [10]. What is often not understood is that vision plays such an enormous role in learning, that even milder problems, which are frequent among children and youth must be considered in school. These problems will be the focus of this chapter. Several vision disturbances, not just decreased VA and VF, have a negative influence on the academic work, sports and leisure activities, and general learning. Such "milder" visual problems are often not addressed even in countries with a highly developed eye health-care system, although many children exhibit them [11]. If these problems are not identified, the children are left without treatment and sometimes even the wrong explanations are given for their learning problems. This may result in frustration, low school results, and a reduced self-esteem. Thus, regular vision screenings may be necessary in finding out whether children have the visual capacity to learn. Screenings are done by eye health professionals, but school-based vision screenings by trained teachers have shown to be effective [12–14].

In this chapter, we will describe and analyze the relationship between vision and learning, the implication of visual problems on reading, and how teachers can screen their students' vision more comprehensively and make interventions as necessary. It begins with (1) an introduction and the description of the methodology we adopted. This is followed up with (2) our inquiry about the relationship between vision and learning, (3) the impact of visual disturbances on reading, and (4) screening and intervention of visual functions through teachers. The chapter concludes with the description of a Continuing Professional Development (CPD) course based on the theoretical framework and results of this literature review.

#### **2. The integrative literature review methodology**

The theoretical framework of the literature review is based on teachers' understanding, identification, and intervention of children's vision and vision screening. Literature sources from various disciplines such as neuroophthalmology, ophthalmology, optometry, education, visual impairment, vision sciences, and vision rehabilitation were used. A thorough integrative literature review approach [15] was conducted to explore the relationship between vision and learning, the impact of

#### *Learning Is Visual: Why Teachers Need to Know about Vision DOI: http://dx.doi.org/10.5772/intechopen.93546*

impaired visual functions on learning, and the reasoning for visual screening and interventions conducted by teachers. In general, a literature review is well suited to review the theories and evidence that exist in a very specific area, such as the role of vision in learning. In addition, a literature review is helpful to provide an overview of the topic. This also seems important since there appears to be a knowledge gap about the relevance of intact visual functions in learning. A literature basis can also be a foundation for the development of a model for new theories and practices. It will be investigated in this chapter whether a new model of teachers' screening and intervention can be derived from the literature review. However, in order to be more specific, it was necessary to narrow down the very broad method of a "literature review." An integrative literature is described as.

*Most integrative literature reviews are intended to address mature topics or new, emerging topics. In the case of mature topics, the purpose of using an integrative review method is to overview the knowledge base, to critically review and potentially re-conceptualize, and to expand on the theoretical foundation of the specific topic as it develops ([15], p. 336).*

The new emerging topic that we would like to address is the greater emphasis that schools and teachers may possibly have in the area of prevention, screening, and intervention of vision problems. We altogether viewed 65 sources, from the years 1901–2020 using various databases and search engines, using keywords such as vision, visual development, visual stimulation, vision screening, and vision screening in schools. The sources were analyzed by the themes established in the introduction, namely, the relationship between vision and learning, the impact of vision problems on learning, and screening and intervention.


**eLEARNING – THEORIES, DESIGN, SOFTWARE AND APPLICATIONS**

http://dx.doi.org/10.5772/2533 Edited by Patrizia Ghislandi

#### **Contributors**

Souhaib Aammou, Khaldi Mohamed, El Kadiri Kamal Eddine, Xinyu Zhang, Lu Yuhao, Blanca C. Garcia, Selahattin Gonen, Bulent Basaran, Fuan Wen, Ileana Hamburg, Ralph Palliam, Patrizia Maria Margherita Ghislandi, Kathleen Scalise, Valarie Akerson, J. Scott Townsend, Ingrid Weiland, Vanashri Nargund-Joshi, Marjan Krašna, Jorge Manuel Pires, Manuel Pérez Cota, Nishantha Giguruwa, Davar Pishva, Anh Dang Hoang

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