The Defocus Method is the current name for the Endmyopia approach to reducing myopia. It is the evolution of the Reduced Lens Method, first published here in 2012. The rename is not cosmetic. The early version described what to do, which lenses to wear and when. Fourteen years of watching what actually moves refractive state narrowed the causality down to one mechanism, and the method is now named after the mechanism rather than the tool.

That mechanism is defocus. Everything else, the differentials, the normalized prescription, Active Focus, the blur horizon, is machinery for controlling the sign of the defocus landing on your retina, hour after hour, for years.

What defocus actually means

Defocus is simply where light comes to a point relative to your retina.

Myopic defocus: light focuses in front of the retina. The image plane sits short of the sensor.
Hyperopic defocus: light focuses behind the retina. The image plane sits past the sensor.

Both states are blur. To you they can look similar. To the retina they are not similar at all, because the retina can tell the difference between them and responds in opposite directions.

The eye is a feedback system, not a fixed object

Eyes are not manufactured to a spec and then finished. They grow into focus, a process called emmetropization. A newborn eye is typically too short, and it elongates until the image lands on the retina, then it is supposed to stop. What tells it when to stop is visual feedback, specifically the sign of the defocus it is receiving.

This is not a fringe claim. It is the most reproduced finding in the myopia literature, demonstrated across chicks, tree shrews, marmosets and rhesus monkeys, in study after study since the 1970s:

Put a minus lens in front of a growing eye. The lens throws the image behind the retina, creating hyperopic defocus. The eye elongates until the image lands correctly again. Remove the lens and the eye is now genuinely, axially myopic. This is called lens induced myopia and it is the standard laboratory method for producing a myopic eye on demand.
Put a plus lens in front of the same eye. The image now falls in front of the retina, myopic defocus. Elongation slows or stops, and in several species the eye shortens.

The signal is largely local to the retina. Sever the optic nerve and the growth response to defocus still happens, which means this is not the brain deciding anything. It is retinal tissue responding to the optical conditions it sits in. It also means the peripheral retina matters enormously, since most of your retina is peripheral.

So the short version of the biology: sustained hyperopic defocus grows the eye longer. Sustained myopic defocus does not. Every part of what follows is downstream of those two sentences.

What a full correction does during close-up work

Here is where the mainstream prescription runs into its own mechanism.

A full distance correction is calculated so that objects at infinity land on your retina. That is correct and useful for driving. Now sit down and read a screen at 40 centimeters while wearing it. Your eye has to accommodate, flexing the crystalline lens, to pull that close image back onto the retina.

Accommodation is not perfect. It habitually falls short of the demand, an effect called accommodative lag, and the amount it falls short grows the closer the object and the longer the session. The image lands slightly behind the retina. That is hyperopic defocus, and it is being delivered to a growing eye for six, eight, ten hours a day, every day, for years.

You do not need a conspiracy to explain progressive myopia. You need only the same mechanism the laboratory uses to induce it, running unsupervised on a school child.

There is a second layer. A standard single vision minus lens focuses the center of your field on the retina but leaves the periphery focused behind it, because of how a spherical lens projects onto a curved retina. So a full correction can deliver central clarity and peripheral hyperopic defocus at the same time, all day.

The industry now agrees, in the products it sells

This is the part worth sitting with. Every myopia control product optometry has launched in the last decade works by imposing myopic defocus:

DIMS lenses (Hoya MiyoSmart) place a honeycomb of small plus lenslets around a clear center, so the periphery receives myopic defocus while the center stays sharp.
MiSight and similar dual focus contact lenses use concentric rings to do the same thing.
Zeiss MyoCare uses a related peripheral defocus design.
Orthokeratology reshapes the cornea overnight, which flattens the center and steepens the mid periphery, producing peripheral myopic defocus during the day.

These products are prescribed, studied and sold on the basis that peripheral myopic defocus slows axial elongation in children, and the trials support it. The mechanism is not in dispute. It is the commercial foundation of the modern myopia control category.

Which leaves an obvious question. If sustained myopic defocus slows the eye down, and sustained hyperopic defocus grows it, why is the default prescription for an adult still a full correction worn for every task including close work?

The trade being made

Put plainly, mainstream correction accepts hyperopic defocus on purpose. Not out of malice, but as a trade.

What it buys is real: immediate clear vision, one simple product, no behavior to learn, no compliance required, and an outcome the patient can verify in the chair within seconds. That is a genuinely good deal on the day you buy it.

What it costs is paid later, by the eye. Sustained hyperopic defocus during close work is the same input the laboratory uses to induce myopia, so the axial length keeps creeping. Next year the prescription is stronger. The stronger lens increases the hyperopic defocus load during the next year of close work, and the year after that the prescription is stronger again.

That structure has a name in every other industry. It is a subscription. The product creates the conditions that require the next version of the product, and the customer is retained for life without anyone having to intend it. Optometry does not need a conspiracy for this to be true. It only needs an incentive structure with no reason to question a treatment that produces reliable repeat business and satisfied customers on the day of sale.

The Defocus Method takes the opposite side of that trade. It gives up instant perfect clarity, which is the part people find hard, and in exchange it works myopic defocus deliberately to walk the eye back from where the correction took it.

What the Defocus Method does instead

The method is three moves, all of them about controlling defocus sign rather than buying a proprietary lens design.

Differentials remove the hyperopic defocus load. A reduced prescription worn only for close work means you are no longer accommodating hard through a distance lens for hours. The single largest daily source of hyperopic defocus is simply switched off. For most people this is what stops things getting worse, before any improvement is on the table.

Normalized keeps a small myopic defocus present at distance. A distance prescription slightly weaker than full correction leaves the far edge of your vision just short of sharp. That deliberate blur is not a compromise or a nuisance. It is the stimulus. A full correction eliminates it completely, which is exactly why a full correction offers the eye no reason to change.

Active Focus engages that edge. Looking at the blur horizon in a relaxed way and letting it briefly clear is the difference between passively wearing weaker glasses, which does very little, and actively working the stimulus.

Then you reduce again as measurements improve. About one diopter a year is the realistic rate for most people. Anyone promising faster is selling something.

The honest boundaries

Concede what should be conceded. The defocus mechanism is established in animal models and accepted enough that the lens industry builds products on it. What is not established in mainstream literature is axial reduction in adult human eyes. The conventional position is that the adult eye does not get shorter, and that measured improvement in adults reflects reduced ciliary spasm, or pseudomyopia, rather than structural change.

Endmyopia’s position is narrower than people assume: refractive state is measurable, it improves at a consistent pace when defocus is managed deliberately, and thousands of people have documented that improvement over years. Whether the axial length number moves, and how much, is a separate argument from whether the diopters do.

Myopia is treated here as a refractive state, something the eye adapts into and can adapt back out of, not an illness. These are scientific ideas rather than medical ones. None of this is licensed, sanctioned or endorsed by the optometry establishment, and it is not medical advice. For any task requiring full acuity, driving above all, wear the full correction the task requires.

Terminology and origin

The Defocus Method is the current name for the framework first published on this site as the Reduced Lens Method on 29 November 2012. Its component terms, Active Focus, differentials, normalized and the blur horizon, were coined here between September 2012 and July 2013, with dated first published use for each recorded in the Endmyopia glossary.

Endmyopia and Active Focus are registered trademarks of Jake Steiner.