An eye-clean diamond is one where no inclusions or blemishes are visible to the naked eye from a normal viewing distance of about 15cm. It's not a grading category on the certificate itself, it's a practical description, and understanding it is one of the most effective ways to spend less on a lab diamond without any visible trade-off.
The clarity scale, briefly
The clarity scale runs from Flawless (FL) at the top down through Internally Flawless (IF), Very Very Slightly Included (VVS1, VVS2), Very Slightly Included (VS1, VS2), Slightly Included (SI1, SI2), to Included (I1-I3) at the bottom. Everything from FL down to VS1 is eye-clean by default. The real value sits at VS2 and SI1, where inclusions genuinely exist but aren't visible without magnification.
Why eye-clean matters more than the grade itself
You don't wear a ring through a 10x loupe. You see it in normal lighting at arm's length, where a VS2 diamond and a VVS1 diamond look identical. The only place that difference shows up is on the certificate and in the price. Choosing an eye-clean VS2 or SI1 over a VS1 or VVS2 is one of the most efficient ways to bring the cost of a lab diamond down without any visible loss of quality.
Which grades are reliably eye-clean
VS2 is almost always eye-clean, inclusions at this grade are small enough that they're not visible without magnification, and it's a solid starting point for anyone who wants reliable eye-clean performance. SI1 is usually eye-clean too, with slightly larger inclusions than VS2 that in most stones still don't show to the naked eye, and it offers the best price-to-performance ratio of any clarity grade. SI2 is not reliably eye-clean; some stones at this grade are, some aren't, so it's worth checking the individual stone or its plotting diagram before buying rather than assuming.
Shape changes what you can get away with
Step-cut shapes like emerald have large, open facets that show inclusions more readily, so VS2 or VS1 is the safer eye-clean floor for those cuts. Brilliant cuts, round, cushion, and oval, mask inclusions far more effectively because of their facet pattern, so SI1 is more reliably eye-clean in those shapes.
Where this fits with what we sell
Every lab-grown diamond ring we make is sourced with eye-clean clarity as a baseline, and every stone ships with an IGI or GIA certificate confirming the exact grade, alongside our full 4Cs of Diamonds guide if you want the complete picture on cut, colour, clarity, and carat together. Moissanite is a separate story: it's produced to high clarity by default, most is VVS or better straight out of the growth process, so clarity is rarely a deciding factor the way it is for diamond. Our 4Cs for moissanite guide covers that in full.
Frequently asked questions
What does eye-clean mean?
No inclusions or blemishes visible to the naked eye at a normal viewing distance of about 15cm. It's a practical standard, not a formal grade on the certificate.
Is VS2 always eye-clean?
In brilliant cuts, almost always. In step cuts it's usually eye-clean but not guaranteed, VS1 is the safer choice for emerald or similar cuts.
Is SI1 worth buying for an engagement ring?
In most cases, yes. A well-cut SI1 round, oval, or cushion is typically eye-clean and offers meaningfully better value than VS2 or higher. We'll always confirm eye-clean performance on the specific stone before you commit.
Can I tell the difference between VS2 and VVS2 on the hand?
No. In normal lighting, at arm's length, they look identical. The difference only shows under 10x magnification.
Does clarity matter for moissanite the way it does for diamond?
Not really. Moissanite is produced to high clarity by default, most is VVS or better, so it's rarely the deciding factor it is when buying a lab diamond.
Browse the full lab diamond engagement ring collection, read our 4Cs of Diamonds guide for the complete grading picture, or start a free design consultation and we'll help you find the clarity grade that gives you the best look for your budget.