Anti-Myopia Exercise Book Performance Evaluation: Optical Testing, Safety Assessment and Applicable

Anti-myopia exercise book evaluation verifies whether the optical properties of paper, the contrast and quality of printed rulings, and the chemical safety of materials genuinely support eye-protection claims. This article explains the evaluation principles, sample requirements, test items, and laboratory methods based on recognized national and international standards such as GB 21027, GB/T 7974, ISO 2469 and ISO 2470. It is a practical reference for manufacturers, schools, and procurement agencies seeking evidence-based verification of anti-myopia workbooks.

Technical Overview

An anti-myopia exercise book is a homework notebook designed to reduce visual fatigue during reading and writing. The evaluation of its anti-myopia effect is not a single measurement but a systematic assessment that combines paper optics, visual ergonomics, print quality, and chemical safety. The underlying principle is that both extremes of paper appearance strain the eyes: excessively bright, bluish-white paper produces glare and high short-wavelength reflectance, while overly dark or dull paper reduces character contrast and forces the eye to work harder.

An effective anti-myopia design typically uses paper with moderate brightness, a slight cream or beige tint, a matte surface with low specular gloss, and clearly legible rulings with balanced contrast. Fluorescent whitening agents, which boost blue-band reflectance, are generally restricted. In addition, because exercise books are in prolonged skin contact with students, chemical safety requirements for student supplies must be satisfied.

The evaluation framework draws on standards published by ISO, CIE and Chinese national standardization bodies, including:

• GB 21027-2020, general safety requirements for student supplies, covering migratable elements, formaldehyde and volatile organic compounds.
• GB/T 7974 / ISO 2470, determination of diffuse blue reflectance factor (ISO brightness, R457).
• GB/T 7975 / ISO 2469, measurement of diffuse reflectance factor of paper and board.
• GB/T 8941, determination of specular gloss of paper at 75 degrees.
• GB/T 1543 / ISO 2471, determination of opacity of paper.
• ISO 11475 and ISO 11476, determination of CIE whiteness under D65 and indoor illumination conditions.
• CIE 15, colorimetry, together with GB/T 3979 and GB/T 7921 for color measurement and color-difference evaluation.
• GB/T 450 for sampling and GB/T 10739 / ISO 187 for conditioning of test pieces.

Testing Samples

Finished Exercise Books

Standard commercial products submitted for evaluation include ruled writing books, square-grid mathematics books, four-line pinyin books, four-line English books, and composition books. Samples are drawn from a production lot according to GB/T 450 so that the results are statistically representative of the batch. Both inner pages and printed rulings are assessed in their finished, bound state.

Anti-Myopia Specialty Books

These are workbooks produced with engineered eye-protection paper, typically featuring controlled brightness, a cream or ivory tint, matte finish, and low or zero fluorescent whitening agent content. The same test program is applied, with particular attention to whether the claimed optical characteristics are actually achieved in the finished product, since printing and binding can alter the appearance of the base paper.

Raw Paper, Cover and Printing Materials

Where a full supply-chain assessment is required, base paper, cover stock, ruling inks, and binding adhesives are tested separately. This allows manufacturers to verify incoming materials and to isolate the source of any nonconformity, such as excessive brightness in the base sheet or restricted substances in the ink.

All test pieces are conditioned to equilibrium in the standard atmosphere specified in GB/T 10739 / ISO 187, normally 23 °C ± 1 °C and 50 % ± 2 % relative humidity, before optical and physical measurements are performed by accredited third-party laboratories.

Testing Items

The test program is organized into five groups of indicators.

Optical Performance of Paper

• ISO brightness (R457) and CIE whiteness, to confirm that paper is neither overly bright nor too dull.
• Spectral diffuse reflectance factor across the visible range, including the blue band around 400 to 470 nm associated with glare and short-wavelength exposure.
• Color coordinates in the CIE L*a*b* system, tint value and color difference against a designated reference, verifying the intended cream or beige shade.
• Specular gloss at 75 degrees, to control glare from the paper surface.
• Opacity, to ensure text on the reverse side does not interfere with reading.

Ruling and Print Quality

• Reflectance contrast between printed rulings and the paper background, expressed as a reflectance ratio or Michelson contrast.
• Line width, line pitch, row spacing and grid dimensions, which influence handwriting posture and character size.
• Print sharpness, ink density uniformity, positional accuracy of rulings and resistance to smearing.

Writing and Durability Performance

• Pencil and ink adhesion, ink penetration and show-through behavior.
• Erasability without surface damage, relevant for repeated homework use.
• Rub resistance of printed rulings under dry and damp conditions.

Physical Properties

• Grammage, thickness and bulk, affecting opacity and writing feel.
• Smoothness (Bekk method) and ink absorbency, which influence legibility of handwriting.
• Folding endurance and binding strength for durability in school use.

Chemical Safety

• Migratable elements, including antimony, arsenic, barium, cadmium, chromium, lead, mercury and selenium, per GB 21027-2020.
• Free formaldehyde and volatile organic compounds.
• Phthalates in plastic components such as polymeric covers.
• Presence and migration of fluorescent whitening agents.

Testing Methods

Spectral Reflectance, Brightness and Whiteness

Diffuse reflectance factor is measured with a calibrated spectrophotometer equipped with a d/0 or d/8 geometry conforming to ISO 2469 and GB/T 7975. ISO brightness (R457) is derived from the reflectance measured through a defined blue filter in accordance with GB/T 7974 and ISO 2470. CIE whiteness values are calculated per ISO 11476 for indoor illumination and ISO 11475 for D65 daylight. For anti-myopia paper, results are commonly judged against a moderate brightness band, for example roughly 60 to 85 percent R457, since values far above this range indicate glare risk while very low values reduce overall page luminance.

Color, Tint and Gloss Measurement

Tristimulus values and CIE L*a*b* coordinates are measured with a standard illuminant and observer as specified in CIE 15, GB/T 3979 and GB/T 7921. A positive b* value confirms the warm, cream tint typical of anti-glare paper, and color difference against a control reference quantifies batch consistency. Specular gloss is measured at 75 degrees per GB/T 8941; anti-myopia products are generally expected to remain in a low, matte gloss range so that light sources do not create reflective hot spots on the page.

Ruling Contrast and Dimensional Parameters

Reflectance of the printed ruling lines and of adjacent unprinted areas is measured under the same geometry, and the contrast is calculated as a reflectance ratio. Adequate contrast ensures the rules guide handwriting without competing with the written characters; excessive contrast is itself a visual stressor. Line width, pitch and row spacing are measured with calibrated dimensional tools or image analysis. Many specifications call for generous line pitch for younger students to accommodate larger handwriting and to encourage an appropriate eye-to-page distance.

Fluorescent Whitening Agent Detection

Screening is first performed by examining inner pages under ultraviolet illumination at 254 nm and 365 nm, where optical brighteners emit characteristic blue fluorescence. Quantitative confirmation is then carried out using extraction and spectrometric methods to determine the presence and migratable amount of fluorescent whitening agents, which should be absent or below the specified limit for products making anti-myopia claims.

Chemical Safety Testing

Migratable elements are extracted with a simulated gastric acid solution and quantified by ICP-OES or ICP-MS in accordance with GB 21027-2020. Formaldehyde is determined by spectrophotometric methods, and volatile organic compounds are analyzed by headspace gas chromatography with mass spectrometric detection. Plastic components are tested for regulated phthalates using solvent extraction followed by GC-MS quantification.

Interpretation of Results

A product is considered to demonstrate an anti-myopia effect only when the full profile is coherent: moderate brightness and whiteness, a controlled warm tint, low gloss, sufficient opacity, adequate but not excessive ruling contrast, appropriate dimensional design, and full compliance with chemical safety limits. Single-indicator claims, such as whiteness alone, are not accepted as sufficient evidence in a professional evaluation report issued by an accredited third-party laboratory.

Applications

Evaluation results for anti-myopia exercise books serve multiple stakeholders:

• Product development and quality control, allowing paper mills and stationery manufacturers to tune furnish, tint, surface treatment and ruling design against measurable targets.
• Compliance verification and marketing claim substantiation, providing documented evidence when a product is promoted as eye-protective or anti-myopia.
• Educational procurement, helping schools and education authorities compare submitted products objectively before bulk purchasing for students.
• E-commerce and retail platform review, supporting the removal of unsubstantiated eye-protection claims and misleading product listings.
• Public health and myopia-prevention programs, supplying standardized data for surveys of school supplies used in national vision-care initiatives.
• Academic research into the relationship between page luminance, contrast and visual fatigue in children.

FAQ

What qualifies an exercise book as anti-myopia?

There is no single magic parameter. A qualifying product must combine moderate brightness, a warm tint, low gloss, adequate opacity, properly contrasted rulings, suitable line spacing and full chemical safety compliance. The evaluation report documents all of these indicators together.

Is whiter paper better for the eyes?

No. Excessively white or bluish paper, often achieved with fluorescent whitening agents, reflects more short-wavelength light and produces glare that increases visual fatigue. Anti-myopia paper deliberately controls brightness within a moderate band and adopts a cream tint.

Are fluorescent whitening agents allowed in anti-myopia books?

For products making anti-myopia claims, fluorescent whitening agents should be absent or below the specified migration limit. Their presence is detected by UV screening and confirmed quantitatively in the laboratory.

What ruling contrast is appropriate?

Ruling lines must be clearly visible to guide handwriting but should remain subordinate to written characters. Contrast is expressed as the reflectance ratio between the printed line and the paper, and typical specifications require a moderate value that avoids both faint, hard-to-follow lines and harsh, high-contrast lines.

How many samples are needed for testing?

Sampling follows GB/T 450 principles, usually requiring a representative number of finished books from the same production batch plus sufficient sheets for replicate optical, physical and chemical measurements. The exact quantity depends on the agreed test scope.

How long does a complete evaluation take?

Optical and dimensional testing, including conditioning, typically requires several working days, while chemical safety analysis, particularly migration and chromatographic tests, may extend the schedule by one to two weeks. An accredited third-party laboratory can consolidate both parts into a single evaluation report.