What Does 6/60, 6/18 or 3/60 Vision Mean? Visual Impairment Categories Explained
Patient with a result like 6/18 or 6/60 in Ahmedabad or Gandhinagar? Dr. Dhaval Patel, MD (AIIMS New Delhi), sees patients at Sadbhaav Eye & Dental Clinic, Motera, Monday to Saturday.
Looking for a simpler explanation, or what power a reading like 6/18 suggests? Read our patient guides on what 6/60, 6/18 and 3/60 vision mean or levels of visual impairment and legal blindness, in plain language.
Last updated: October 2026
Key points in 60 seconds
- 6/60 means you see at 6 m what a normal eye sees at 60 m; it is the top letter of the chart.
- In India (RPwD Act 2016) blindness is best-corrected acuity worse than 3/60 in the better eye, or a field under 10ยฐ.
- Low vision is 6/18 or worse, down to 3/60, or a field under 40ยฐ down to 10ยฐ.
- The old 1995 cut-off of 6/60 for blindness no longer applies; the criteria use the better eye with glasses.
- WHO categories use presenting vision; the US legal blindness cut-off is 20/200 (6/60).
Pages on this topic
- This page: For doctors: RPwD 2016, WHO and US criteria for low vision and blindness
- For patients: what 6/18 or 6/60 means and the glasses power
- For patients: low vision vs legal blindness in India
Quick answer: what each value means
| Vision (metres) | US (feet) | What it means | India (RPwD 2016)* | WHO category |
|---|---|---|---|---|
| 6/6 | 20/20 | Normal vision | โ | No impairment |
| 6/9 | 20/30 | Slightly below normal | โ | No impairment |
| 6/12 | 20/40 | Mildly reduced. Often still enough for daily tasks. | โ | No impairment |
| 6/18 | 20/60 | Noticeably reduced. Small print and distant signs are hard. | Low vision | Mild impairment |
| 6/24 | 20/80 | Moderately reduced | Low vision | Moderate impairment |
| 6/36 | 20/120 | Moderately to severely reduced | Low vision | Moderate impairment |
| 6/60 | 20/200 | Can read only the top letter of a standard chart. This is the US legal blindness cut-off. | Low vision | Moderate impairment |
| 3/60 | 20/400 | Can read the top letter only from 3 metres | Low vision (the lower limit) | Severe impairment |
| Worse than 3/60 (2/60, 1/60, finger counting) | Worse than 20/400 | Very poor vision, but not necessarily total blindness | Blindness | Blindness |
*India's categories apply to best-corrected vision (with glasses) in the better eye. A narrowed field of vision can also qualify: under 40ยฐ (down to 10ยฐ) counts as low vision, and under 10ยฐ as blindness. WHO categories use presenting vision in the better eye.
Important: India's legal definition of blindness changed in 2017 โ this page reflects the current definition under the Rights of Persons with Disabilities (RPwD) Act, 2016, which replaced the older 1995 Act. If you trained on or remember the older 6/60 cutoff, note that the threshold is now stricter.
Current definition of blindness (RPwD Act, 2016)
A person is certified as blind if, after best correction, they have any of the following:
- Total absence of sight; or
- Visual acuity less than 3/60 (or less than 10/200 Snellen) in the better eye; or
- Limitation of the field of vision subtending an angle of less than 10 degrees
This is stricter than the older 1995 Act criterion, which set the threshold at visual acuity not exceeding 6/60 (20/200) or a field of 20 degrees or worse.
Current definition of low vision (RPwD Act, 2016)
A person has low vision if, with best possible correction, they have any of the following:
- Visual acuity not exceeding 6/18, or less than 20/60, down to 3/60 (or up to 10/200 Snellen) in the better eye; or
- Limitation of the field of vision subtending an angle of less than 40 degrees, down to 10 degrees
Why this matters practically
The RPwD Act, 2016 replaced the 1995 Persons with Disabilities Act and expanded recognised disabilities from 7 to 21 categories (blindness and low vision remain two of them). This is the legally operative definition today for disability certification, benefits eligibility (reservations in education and employment, free public transport, examination scribe assistance, and other statutory benefits), and any current medical board assessment in India โ not the older 1995 criteria some textbooks and older references still cite.
WHO definition, for comparison
The World Health Organization's ICD-11-based definition differs again: a person is visually impaired if presenting visual acuity in the better eye is worse than 3/60, with near vision impairment now also included (presenting near VA worse than N6 with correction). Note that India's National Programme for Control of Blindness (NPCB; renamed NPCBVI in 2017, which adopted the "worse than 3/60" cut-off) historically used yet another threshold (20/200) based on presenting rather than best-corrected acuity โ so when discussing "blindness," always be explicit about which definition (RPwD 2016, WHO/ICD-11, or NPCB) is being used, since the numbers differ.
US definition (20/XX notation), for comparison
If you're used to the American 20/XX Snellen notation rather than India's 6/XX metric system, here's the direct equivalent โ both measure the exact same thing, just at different testing distances (20 feet vs. 6 metres):
| US (feet) | India/UK (metres) | Meaning |
|---|---|---|
| 20/20 | 6/6 | Normal vision |
| 20/40 | 6/12 | Mild impairment |
| 20/60 | 6/18 | Mild-moderate impairment |
| 20/100 | 6/30 | Moderate impairment |
| 20/200 | 6/60 | Severe impairment / US legal blindness threshold |
| 20/400 | 6/120 | Profound impairment |
In the United States, the Social Security Administration defines legal blindness as visual acuity of 20/200 or worse in the better eye with best correction (equivalent to 6/60), or a visual field of 20 degrees or less in the better eye โ this is the operative US definition for disability benefits, distinct from both India's RPwD 2016 threshold (3/60) and the WHO/ICD-11 threshold.
Older certification categories (2001 guidelines), for reference
Note: the table below is the older category system that many textbooks still print. Since January 2018, certification follows the Ministry of Social Justice and Empowerment's revised guidelines, which grade both eyes together into finer categories (for example 3a, 3c, 4a and 4b). A certificate is issued only for benchmark disability of 40% or more. Use the current gazette notification when certifying.
| Category | Better eye | Worse eye | % Disability |
|---|---|---|---|
| I | 6/18-6/36 | 6/24 to Nil | 40% |
| II | 6/40-4/60 or field 10-20° | 3/60 to Nil | 75% |
| III | 3/60 to 1/60 or field <10° | F.C. at 1ft to Nil | 100% |
| IV | F.C. at 1ft to Nil or field <10° | F.C. at 1ft to Nil | 100% |
| One-eyed person | 6/6 | F.C. at 1ft to Nil or field <10° | 30% |
F.C. = Finger Count. This categorization framework guides percentage disability certification โ always verify against the current gazette notification when issuing an actual certificate, as specific percentage assignments are periodically updated by the Ministry of Social Justice and Empowerment.
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Key references: The Rights of Persons with Disabilities Act, 2016 (India). | Ministry of Social Justice and Empowerment, Guidelines for Assessment of Visual Disability. | Understanding definitions of visual impairment and functional vision. Community Eye Health J.
๐ Want the exam-ready deep dive? This topic, and much more is covered in Ophthalmology Explorer (A High-Yield Clinical Reference for Ophthalmology Residents, Fellows & Board Exams) โ available on Kindle. See all my books.
Need a vision or visual field assessment? Read about visual field testing at Sadbhaav or book a consultation with Dr. Dhaval Patel.