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The best method for making the latent hypermetropia manifest is through the recession method. It consists principally is placing two positive lenses of 1.00/1.50D in front of each eye which have already in front of them the correction for farsightedness; the patient is asked to observe the optotype from .5 meter distance. Then the optotype is pulled further away till the picture becomes hazy; slowly, always starting from a 50cm distance and pulling the optotype away from the patient up to 5 meters one can arrive at a relaxation of the accomodation.

The above described method is used involuntarily by many presbytes who, corrected with reading glasses, often raise their eyes to look at distant objects not remembering to lower or to remove their glasses.

From Optometria e Oftalmologia by Prof. Sergio Villani (Volume One)

Related article: Correction of Hypermetropia with binocular vision

After each eye has been corrected separately, we often find that the eyesight has remained the same even when adding two slightly positive lenses on each eye. The quantity of added power without worsening the eyesight is equal to that of the accomodation that is being relaxed. This can be possible only for +.25D but usually one can achive higher powers: up to +1.00D and even more.
As a rule, the younger the subject, the higher the relaxed quantity and vice-versa.
If, in the case of exophoria, the quantity of manifest hypermetropia becomes an essential condition, it is recommended to take the measurement and to prescribe the quantity found with binocular vision.
Often in subjects that are supposed to be emmetropic, taking the measurements, a slight hypermetropia is encountered.
If exophoria is present, it can happen that we find a certain amount of hypermetropia in monocular vision while it is less with binocular vision.
This result, which shows the opposite of what we said before, is justified by the fact that with monocular vision convergence is not stimulated, the hypermetropia shows itself more completely when there is no convergence effort to bring the visual axes in parallel. If also the accomodation is stimulated, the correction found with monocular vision is too strong.
The correction of latent hypermetropia, measured binocularly, can show various values for a small part of the hypermetropia which is some moments may overcorrect resulting in a fuzzy eyesight.

From Optometria e Oftalmologia by Prof. Sergio Villani (Volume One).

Related articles: Measuring hypermetropia by defocusing

We have said before that measuring hypermetropia, continuing to increase the power of the lenses, one will find one that worsens the eyesight and thus to use one before the eyesight became fuzzy.
The defocusing system works like this: if the maximum positive power which enables to read 10/10 is a +2.00D and a +3.00D lens worsens the eyesight, one goes backwards trying a +2.75D lens, a +2.50D lens, etc. With a latent hypermetropia one can certainly achieve a 10/10 eyesight with the initial lens power > +2.00D.
Important in this operation is that the more powerful lens is not removed before the weaker lens is put in front of the eye.
Also with this technique, to achieve the maximum positive correction possible, it is desirable to make the measurements on both eyes. Even if there are doubts on the efficiency of this system to obtain the maximum measure of manifest hypermetropia, it is a better system than to increase the power of the lenses gradually.

From Optometria e Oftalmologia by Prof. Sergio Villani (Volume One).

Related articlesi: Various types of prescription graduated lenses

Hypermetropia is objectively determined ascertaining and measuring the refractive cabilities of the eye, using positive lenses. If an eye is hypermetropic, one increases the power of the lens till the eyesight worsens; the lens preceeding this one gives us the degree of manifest hypermetropia.
This lens is the most powerfull for a good eyesight; if we increase the power by .25 the eyesight worsens, if we decrease it by .25 there is no change.
The reason is that .25 more renders the eye myopic, while .25 less makes no difference.
Therefore if a subject of 20 years has a manifest hypermetropia of 1.50 D, it is probable that the subject sees the same with 1.25 and with 1.50 while 1.75 produces less eyesight.
One can say therefore that the +1.50 cures the manifest hypermetropia and, as is logical to expect, the +1.75 turns the eye into a .25D myopic; on the other hand a weaker lens does not diminish the eyesight but forces a greater accomodation.

From Optometria e Oftalmologia by Prof. Sergio Villani (Volume One).

Related article: Determining the hypermetropia