The study was conducted in Shri Sathya Sai Medical College and Research center, Ammapettai, Chennai, India. After the Institutional Ethical committee clearance was obtained an advertisement was put up in the college campus asking for volunteers. A total of 100 subjects were selected from faculty, office staff, technical staff and students on first come first serve basis.

The participants were informed of the procedure and purpose of the study and informed consent was obtained in writing. Only subjects with visual acuity of 6/6 were selected for the study. The subjects were asked to perform a set of writing tasks in the space provided in the proforma.

Myopia was induced in the participants by giving plus spherical lenses from the trial set starting from +0.5 D power with serial increments of +0.5D up to 4 D as the subjects reported significant diminution of vision preventing them from continuing further. The tasks were repeated for each of the plus lens given. Pens to perform the task were provided to maintain uniformity in the data collected and avoid error introduced by defective pens.

After the performance of all the tasks the proforma were collected and assessed for a set of class characters. Class characters like font size, orientation, style, curvature, letter form, stability, slant, fluency, copying skills, etc were evaluated. For the purpose of the study 13 standard variables for the handwriting were analysed repeatedly with every increment of plus lens given. The data was compiled & statistically analysed using SPSS (Statistical Package for Social Sciences) computer software (version 16).

The sample of the study consists of 100 (68 male & 32 female) subjects between 18-38 years, with the mean age of the participants being 23.3 years. As the study is planned in Chennai most of the participants are Tamil (78%) speaking.

As required in this study 13 variables were repeatedly measured in the handwriting with every 0.5 D increment of the plus lens. The changes in the variable were compared to the handwriting character of the subject when the task was performed for normal vision. The difference in their means was studied. To check for the variance and its statistical significance multivariate analysis (MANNOVA) was used. The results of the same for relevant variables are presented in [Table/Fig-1,2,3,4,5,6,7,8 and 9].

[Table/Fig-1]:

Figure showing the different zones of letters in cursive writing and the measurement of letter size

Letter size: For the purpose of handwriting analysis in cursive writing the letters are said to have three zones, usually termed as the upper zone, middle zone and lower zone. Normally this corresponds to the four line book used by children to practice writing. The average size of the letters in ones cursive writing was measured with calipers in letters having both upper and lower zone like letters ‘L’ & ‘T’ [Table/Fig-1]. The mean letter size [Table/Fig-2] in all grades of myopia is larger compared to that in normal vision. There is a statistically significant difference [Table/Fig-3] in the average letter size of the handwriting with serial increments of myopia, F (200, 528) = 2.144, p < .0005; Wilk’s A=0.011.

Further supporting the above findings [Table/Fig-4] shows that the mean upper zone and lower zone size of the handwriting at different grades of myopia is higher compared to that in normal vision. As size of objects visualised proportionally increases with serial increments in myopic lenses, the writing size also increases probably due to this perceptual defect. However as these changes are not proportional to the grade of induced myopia they can’t be used to predict the same. Change in the writing size can be clinically considered as an indicator of myopia.

Ideally the middle zone in normal adult writing would measure to be 3mm [7]. This is an accepted international norm. Thus the middle zone can be divided into three probable types [Table/Fig-5]. Multivariate analysis (F (104, 554)= 2.89, p < .0005; Wilk’s A= 0.051, partial η2 = 0.311.) shows a statistically significant variation in the mid zone size but from the [Table/Fig-5,6] it is not very clear if the size primarily increases in a graded manner. The extent of change noted with every grade of myopia is variable and inconsistent. But what can be safely concluded is that the size of letters in all zones increases with change in the visual acuity and the change is not proportional to the grade of myopia. This finding finds support in various studies [7,9,10–13] quoted in the references.

It has been found that visual perceptions contribute significantly to the perceptual skills necessary for writing. The visual-motor coordination is the ability to match motor output with visual input. It is a process of integrating information derived from both visual and the motor systems to optimize the movement pattern, to reduce the amount of time and energy spent to reach the desired writing outcome [14]. While writing, the visually impaired have to judge the form, length, and location of strokes without references. Partial vision can provide a few guides and the availability of these reference points may determine the quality of the writing or lettering. There is misalignment of letters, words with one another and of writing with respect to a ruled or implied baseline. There is some increase in letter sizes compared to the previous handwriting. Also, documented are overlapping of words, infrequent pen lifts and absence of “t” crossings in cursive writing and unrepaired occurrences of pen failure creating voids in ink deposits. A lack of fluency and infrequent introduction of hesitation marks or scratches are also noted [7,9–13].

Space between lines: - When writing in an unruled surface the writer has to judge his relative positioning based on his own letter spacing. Space between the lines was measured in millimeters [Table/Fig-7]. Statistically significant (F (189, 460) = 3.165, p < .0005; Wilk’s A= 0.003) variation in the spacing of the lines is noted, similar to that noted by Huber [7] and various other researchers [9–14]. However the change is inconsistent, with the spacing decreasing in some grades of myopia and increasing in some.

Ability to stay on line: - From [Table/Fig-8] it is clear that the ability to stay on line while writing decreases with serial increments of myopia. This could be due to blurring of vision with higher grades of myopia affecting one’s ability to perceive the base line. This is consistent with findings of Huber [7] and various other researchers [9–15]. Mischio writes that there are several vision-related skills that are critical to good handwriting that may be underdeveloped in a student with vision problems [13]. Peripheral awareness & spatial concepts are required to know, plan and write in a straight line. Visualization is required to remember the word form. Good laterality and directionality are required for recognizing similar patterns.

Omission of words: - With progressive blurring of vision it is expected that the writer face difficulties in reading and hence omit words while copying. At higher grades of myopia (>2.5D) few (9%) subjects omitted words in the sentences they were copying. Similar findings were reported by Huber et al., Wilson et al., William et al., Tukel S et al., & Sanghvi et al., [7,9,12,14,15]. Literature published from experience in learning difficulties in children does suggest the influence of vision on the writing outcome. The following writing tasks were observed to be significantly difficult in children with visual impairment. Children had difficulty copying from whiteboard or book. They omitted or repeated letters, words, or phrases, had poor eye-hand coordination including poor writing & wrote too slowly. These children were found to have poor finger movement in writing [16].

Pastiosity:- Fatigue in writing and difficulty in maneuvering the pen sometimes cause a delay in the flow of writing. This causes the pen to blotch due to excessive flow of ink. The transient phenomenon causes repeated marking on the letters termed as pastiosity. Pastiosity count is the number of times this phenomenon occurs in a particular word [7]. One particular word was selected for this purpose and studied in all grades of myopia and compared in the [Table/Fig-9].

Form the tables it is clear that the mean pastiosity count of the writing increases proportional to the degree of myopia induced. The mean pastiosity count at normal vision was 2.16 times and at induced myopia of 4D it was 3.87 times. Blurring of vision could lead to decreased speed of writing and maneuvering curved letters leading to increased pastiosity. We could not find any significant literature showing similar find in writing except for suggestions by Huber et al about increase in the pastiosity with visual impairment [7].

From the findings of the study it can be concluded that myopia significantly influence the handwriting and any change in visual acuity would induce corresponding changes in the handwriting characters. There is increase in letter size, pastiosity where as the ability to stay on line and space between the lines decrease in different grades of myopia. The changes are not linear and can’t be used to predict the grade of myopia but can be used as parameters suggestive of refractive error. These findings or parameters in children with myopia after assessment may help in overall development of children with myopia and improve their performance in school