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Vision/Eye Test (Basic)

Assess your visual acuity and eye health metrics. Convert Snellen ratios to decimal acuity, MAR, and visual efficiency with personalized recommendations.

Visual Acuity Test

Enter your Snellen acuity measurement

Visual Acuity (Snellen)

e.g., 20/20, 20/40, CF, HM

Age

1-120 years

Glasses / Contacts

YesNo

Currently wearing

Normal Vision

Visual acuity within normal range

Decimal Acuity

1.00

MAR

Visual Efficiency

100%

Your vision is within normal range. Continue with regular eye exams to maintain good eye health.

Vision Acuity Reference Guide

Normal Vision

20/10 – 20/25 (Decimal: 2.0 – 0.8)

Reduced Vision

20/30 – 20/70 (Decimal: 0.67 – 0.29)

Visually Impaired

20/80 and worse (Decimal: 0.25 and below)

Severe Impairment

CF, HM, LP, NLP — Immediate professional care

MAR = Minutes of Arc. Visual Efficiency = (Decimal Acuity / 1.0) × 100%.

This calculator provides general guidance only. For accurate vision assessment, please consult a licensed eye care professional.

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Applications

Used by individuals who want to understand their visual acuity measurements and get recommendations for eye care. Helpful for preliminary self-assessment before visiting an optometrist.

The Formulas

Decimal Acuity = Snellen numerator / Snellen denominator (e.g., 20/40 = 0.5). MAR (Minutes of Arc) = 1 / Decimal Acuity. Visual Efficiency = (Decimal Acuity / 1.0) × 100%, capped at 100%.

Fun Fact: The Snellen chart was invented by Dutch ophthalmologist Herman Snellen in 1862. The famous 20/20 vision notation doesn't mean perfect vision—it means you can see at 20 feet what a person with normal vision sees at 20 feet.

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