A refractive error is a health related condition of the eye that causes visual impairment and may lead to blindness if not early detected and corrected. It is a disorder that occurs when parallel rays of light entering the non-accommodating eye are  not focused on the retina. Refractive error is classified into three categories: myopia (near sightedness) – this is difficulty in seeing distant objects clearly, hyperopia also known as hypermetropia (farsightedness) – this is difficulty in seeing close objects clearly, and astigmatism – this is distorted vision resulting from an irregularly curved cornea [1]. Refractive error is one of the most common determinants of visual impairment worldwide, particularly among children, and frequently remains undiagnosed for long periods [2]. Childhood visual impairment due to refractive errors is a significant problem among school children and has a considerable impact on public health. Recent data suggested that a large number of people are blind in different parts of the world, due to high refractive errors because they are not using appropriate refractive corrections. The impact of blindness due to refractive error is considered in terms of  years of blindness, a person becoming blind due to refractive error at ayoung age, and which is not corrected, would suffer many more years of blindness than a person becoming blind from cataract inold age and would place a greater socioeconomic burden on society [3].Visual impairment and blindness due to refractive error can hinder education, personality development, and career opportunities, in addition to causing an economic burden on society. The prevention and cure of refractive errors should provide enormous savings and facilitate societal development [4]. Refractive error can be detected through routine examination of patient who present to clinics, or through vision screening of the population at large. The former approach may work satisfactorily in developed countries, but the latter is necessary in developing countries because a large majority of the population does not have access to reasonable quality eye care services. Vision screening is most commonly carried out on school children, which is a valuable method of identifying potentially treatable ocular abnormalities, including blindness due to refractive errors. Community vision screening is another approach that involves door- to- door surveys by trained field workers to assess visual acuity and identify people with vision problems [5].Refractive error is the most easily treatable cause of visual impairment following an appropriate refractive correction, such as spectacles, contact lenses, or refractive surgery. Spectacles are the most commonly used form of refractive correction since they are the most inexpensive and the simplest of the three options; as such, they are the most appropriate treatment for refractive error in developing countries. All three forms of treatment for refractive error are relatively easily available and more affordable to individuals in developed countries [6]. Due to increasing realization of the enormous need for correction of refractive error worldwide, refractive error has been considered one of the priorities of the recently launched global initiative for the elimination of avoidable blindness: VISION 2020 -  The Right to sight [7]. Early detection of the refractive errors is very much important to prevent blindness and other complications. Therefore the knowledge regarding the refractive errors among school teachers is very much important to detect any manifestations of refractive errors in school children. Hence the researcher selected this study to find the knowledge of school teachers regarding refractive errors and also to provide additional information to them which will be helpful in detecting early manifestations of refractive errors in school children.

The research approach adopted for the study was quantitative approach and the design was one group pretest posttest design.

24  school  teachers  were  selected  using  convenient  sampling technique which is a non-probability method of sampling. Independent variable in the study was teaching programme and dependent variable was knowledge of school teachers regarding childhood refractive errors. Data were collected using two structured tools. Tool 1: Socio-demographic tool and Tool 2: Structured questionnaire to assess the knowledge regarding childhood refractive errors. Validity of the tool was assessed by giving tools to 5 experts in the field of nursing and medicine. Modifications were done as per the suggestions given by the experts. Test retest method r=(0.88) was used to assess the reliability of the tools. Obtained permission from the principals and informed consent was taken from the teachers. Pilot study was conducted among 6 teachers to check the feasibility and practicability of the study. The study was sound to be feasible. The data was tabulated and analysed using differential and inferential statistics like percentage, mean, standard deviation, paired t test and chisquare test.

Section A: Description of sample characteristics(Table 1) shows that out of 24 samples majority, 29.2% belongs to the age group of 36- 40 years and 46 – 50 years.100% of subjects were females. 83.3% were Christians.100% of subjects was married. 83.3% have educational status of B Ed. 54.2% belongs to nuclear family and 87.5% were have monthly income 10000 – 20000.

Table 1: Frequency and percentage distribution according to age, sex, religion, education, marital status, type of family, monthly income (n=24).

Section B: Evaluation of knowledge of school teachers regarding childhood refractive errors

Table 2 shows that the mean of pretest is 7.33, posttest is 12.50 and standard deviation of pretest is 3.06, posttest is 2.25.

Table 2: Mean and standard deviation of pretest and posttest knowledge score (n=24).

Table 2 shows that the mean of pretest is 7.33, posttest is 12.50 and standard deviation of pretest is 3.06, posttest is 2.25.

Table 3 deals with the frequency and percentage distribution of pretest and posttest knowledge. In pretest 83.35% belongs to poor category (below 10), 12.5% belongs to average category (10– 13) and 4.2% belongs to good category (14 – 16). In posttest 54.2% belongs to average category, 25% belongs to good category, 16.7% belongs to poor category and 4.2 % belongs to excellent category.

Table 3: Frequency and percentage distribution of pretest and posttest knowledge (n=24). (n=24).

Table 4: Comparing the effectiveness of pretest and posttest knowledge level of school teachers (n=24).

Table 5: Association between knowledge and selected socio demographic variables (n=24).

Table 4 deals with the comparison of effectiveness of pretest and posttest knowledge level of school teachers. Here the p value is

0.001 and this shows that the teaching programme was effective.

Section C: Association between knowledge and selected socio demographic variables

Table 5 deals with the association between knowledge and selected socio demographic variables. The level of significance is 0.05 and p value of age is 0.220 so there is no association between age and knowledge. The p value of religion is 0.54 and there is no significant association between religion and knowledge. The p value of education is 1 and there is no significant association between education and knowledge. The p value of type of family is 1 and there is no significant association between type of family and knowledge. The p value of monthly income is 0.32 and there is no significant association between monthly income and knowledge.

A cross sectional study was conducted to identify the prevalence of refractive errors in school children (12-17 years) of Ahmadabad city by age, sex, class and type. The sample size was 1,647 school children which included 828 males and 819 females. Result showed that 25.32% of the students were found  to be having refractive errors. Of these 47% were females and 53% were males. The distribution of refractive errors was  myopia - 63.5%, hypermetropia -11.2% and astigmatism- 20.4% [8-13]. A study was conducted regarding refractive errors among adolescents attending ophthalmology OPD. All adolescents coming to ophthalmology OPD, in the age group of 12- 17 years for minor eye problems were included in the study. Overall 1000 children in the age group of 12-17 years were examined for refractive errors. Data was collected from January 2002 to July 2002. Among 1000 adolescents who were examined, 124 children were found to have refractive errors. The overall prevalence of refractive errors in the study was found to be 12.5%, which included myopia in 69 (55.6%) cases, hypermetropia in 16.9% cases and astigmatism in 27.4 % [14,15]. A study was done on uncorrected refractive errors in urban school children. Three schools in Rohtak city, India were selected for this study by using random method. 678 students belonging to age group 5-10 years were included in this study. A total of 678 students were examined. Out of these 83(12.42%) were not able to see 6/9 line on Snellen”s distance visual acuity chart with one or both eyes and were referred. One static retinoscopy, 76 of these students had refractive error whereas 7 had normal retinoscopic pattern bringing the overall prevalence of uncorrected refractive error to 11.37%. Hyperopia was present in 5.14% of children, myopia in 3.23% and astigmatism in 3% of children [11]. Chitra N conducted an experimental study in Banglore to assess the effectiveness of structured teaching programme on prevention of refractive errors. The pretest was conducted. Structured teaching programme was given with slide show. On the 8th day after structured teaching programme, the post test was conducted. In pre-test 100% subjects had inadequate knowledge. In post-test 80% subjects had adequate knowledge [16].

The conclusion drawn from the study has shown that teaching programme regarding childhood refractive errors among school teachers was effective in terms of improving their knowledge. There is an immense need of creating awareness among school teachers regarding childhood refractive errors for early identification of childhood refractive errors among school children.

1. Bronwyn H, Jennifer BD, Jojo DU, Katrina SL, Karen FM, Rhondelle Retrospective analysis of refractive errors in children with vision impairment. 2005; 82: 807-816.
2. Prevention of blindness and visual impairment. Priority eye diseases, 2008.
3. Udom OD, Uduak CE. Prevention and management of refractive error blindness in nigeria: the role of private optometrists, the inaugural world congress on refraction error and service development, 2007.
4. Murthy GVS. Vision Testing for Refractive Errors in Schools 'Screening' Programs in Schools. J Community Eye 2000; 13: 3-5.
5. Refractive error blindness. Bulletin of the World Health Organization. 2001; 79: 237-243
6. Visual Impairment, Refractive Error, WHO Global info base, 2008.
7. Donato JJ. Classification of refractive errors. Med Bull US Army Eur. 1963; 20: 83-86.
8. Kartha GP, Sethi S. Prevalence of refractive errors in school children (12-17years) of ahmadabad city. Indian J Community Med. 1987:
9. Dandona R, Dandona Refractive errors in an urban population in Southern India : the Andhra Pradesh Eye Disease Study.
10. Childrens, Refractive error and eye ailment management (CREAM) Project.
11. Batra BN. Prevalence of refractive errors in school First Asian and second national medical student’s research conference. 2008; 638.
12. Prevention of blindness and visual impairment. Priority eye diseases, 2008.
13. CS Dhull, Verma M, Singh SV. Uncorrected refractive errors in urban school North zone ophthalmological society. 2004.
14. Matta P, Matta Refractive Errors among adolescents attending Ophthalmology OPD. Indian J Community Med. 2006.
15. Kumar BS, Uzma A comparative clinical survey of the prevalence of refractive errors and eye diseases in urban and rural school children. Indian J Community Medicine. 2007; 35.
16. Zalawadiya S, Trivedi Prevalence of refractive errors in children (age group 7-15 years) of rural and urban area of gujarat: a population based study. J Community Eye Health. 2003; 32.