PeekVision Test Methodology

Purpose of PeekVision

PeekVision is a browser-based informational vision screening tool. It is designed to help users perform a preliminary check of visual acuity and color vision using a computer or compatible mobile device.

PeekVision is not intended to provide a medical diagnosis, prescription, or replacement for a comprehensive eye examination.

Last reviewed: September 14, 2026

Visual acuity screening

Visual acuity describes the ability to resolve fine visual detail. PeekVision presents progressively smaller letter optotypes and records the smallest level that the user reports being able to read.

The standard screening uses Sloan-style letters and presents five letters per level.

Testing can be performed separately for:

• Right eye — OD
• Left eye — OS
• Both eyes — OU

Testing each eye separately can help reveal differences between the eyes that may not be obvious when both eyes are open.

Snellen visual acuity

PeekVision reports visual acuity using familiar Snellen-style values such as 20/20, 20/40, and 20/100.

In a Snellen measurement, the first number represents the standard testing distance in feet. The second number indicates the distance at which a reference observer is expected to resolve the same level of detail.

For example, 20/40 means that the tested level of detail seen at 20 feet corresponds approximately to detail a reference observer may identify at 40 feet.

logMAR representation

PeekVision also uses logMAR internally to represent visual acuity levels. logMAR is a logarithmic visual acuity scale commonly used in clinical research and standardized acuity measurement.

Standard Vision Test

The Standard Vision Test begins with relatively larger optotypes and progresses toward smaller acuity levels as the user indicates that letters remain readable.

The current screening sequence covers approximately:

20/50 → 20/40 → 20/32 → 20/25 → 20/20 → 20/16 → 20/13 → 20/10 → 20/8 → 20/6 → 20/5 → 20/4.

Users indicate whether the displayed row can or cannot be read. Results depend on following the viewing-distance and test-condition instructions as closely as possible.

Accessible Vision Test

PeekVision includes an accessible screening mode intended to make the test easier to use for people who may have difficulty interacting with smaller controls or standard test interfaces.

Accessibility features include:

• Large high-contrast letters
• Large response controls
• Spoken instructions
• Optional voice responses
• Manual response fallback
• No requirement to respond within a short time limit

Test letters themselves are not read aloud because doing so would reveal the answer.

The accessible screening focuses on larger acuity levels ranging approximately from 20/400 through 20/50.

Distance and near screening

PeekVision supports both distance and near screening modes.

Users should follow the viewing-distance instructions shown by the application. Distance from the screen matters because the angular size of an optotype changes when the viewing distance changes.

Near testing is intended to provide a preliminary assessment of close-range visual performance under the specified test conditions.

Correction status

Users can indicate whether the screening is being performed with their normal glasses or contact lenses.

This information provides context for the screening result. PeekVision does not determine a spectacle or contact-lens prescription.

Color vision screening

PeekVision includes a browser-based color vision screening using colored-dot plates designed to evaluate recognition of color patterns.

Color screening can be affected significantly by:

• Display calibration
• Screen brightness
• Night mode
• Blue-light filters
• Operating-system color filters
• Ambient lighting
• Display technology

For this reason, online color testing should be treated as screening rather than a diagnostic color vision examination.

Screen calibration and physical size limitations

Browsers do not always provide a reliable measurement of the true physical size of a display.

Differences in monitor size, device pixel density, operating-system scaling, browser zoom, and display configuration can influence the physical size of letters shown on screen.

Future versions may incorporate additional physical screen calibration methods to improve consistency across devices.

Testing environment

For more consistent results:

1. Use a well-lit room.
2. Avoid glare and reflections on the display.
3. Keep the browser zoom at its normal setting.
4. Follow the specified viewing distance.
5. Test one eye at a time when instructed.
6. Wear your normal correction when appropriate.
7. Do not memorize or repeatedly rehearse the displayed letters.

Eye-to-eye comparison

The PeekVision report compares results from the right and left eyes. A noticeable difference between the two eyes may be worth discussing with an eye-care professional, particularly when the difference is persistent or accompanied by symptoms.

The comparison is a screening aid only and does not establish a diagnosis.

What PeekVision can help identify

PeekVision may help a user recognize that:

• Visual acuity appears reduced under the test conditions
• One eye performs differently from the other
• Color patterns are difficult to recognize
• A professional eye examination may be appropriate

What PeekVision cannot diagnose

PeekVision does not diagnose:

• Myopia, hyperopia, or astigmatism
• Glaucoma
• Cataracts
• Retinal disease
• Macular degeneration
• Diabetic eye disease
• Neurologic causes of vision loss
• Color vision deficiency as a formal clinical diagnosis
• Any other eye or medical condition

A comprehensive eye examination may include refraction, slit-lamp examination, retinal examination, intraocular pressure, visual field testing, binocular vision testing, and other procedures that cannot be performed by PeekVision.

When to seek professional eye care

Consider arranging an eye examination if:

• Your vision screening result is reduced
• Your two eyes differ noticeably
• Your vision has changed over time
• You have difficulty seeing despite normal screening results
• You have concerns about color perception
• You are due for a routine eye examination

Privacy-focused browser screening

PeekVision is designed to perform the current screening experience through the browser without requiring users to create an account.

Voice features may require microphone permission when used. Users can choose manual controls instead of voice responses.

See the PeekVision Privacy Policy for additional information.

Learn more or start a screening

You can continue with the appropriate PeekVision resource:

• Free Online Eye Test
• Visual Acuity Test
• Accessible Vision Test
• Color Vision Test
• What Is 20/20 Vision?

Important disclaimer

PeekVision provides informational screening only. Results should not be interpreted as a medical diagnosis, prescription, or certification of visual fitness.

If you have concerns about your eyesight or eye health, consult a qualified optometrist, ophthalmologist, or other appropriate healthcare professional.