Analogously, in the medium to high astigmatism, especially if associated with hypermetropia it is advisable to wear the correction as often as possible. In theory, this should be valid for all cases of astigmatism, given that it cannot be compensated with the sole accomodation. In practice, however, the astigmatism less than 0,50 D can be treated like a slight hypermetropia, i.e., the prescription should consider only the close-by work because the vision at a distance is usually not much impaired. Often, though, the slight astigmatisms are very disturbing caused by the continuous attempts to focus, arriving sometimes also at accomodative spasms. Exceptions to the rule, regarding the hypermetropia, are for children. Practically in all cases of strabism it is necessary to wear glasses and for very small children, even if the emtropia is slight, it is often preferrable to prescribe glasses to wear permanently, avoiding the disturbances that derive from putting them on and off frequently.
Art. 5/7 Related article: The Correction to Prescribe when the Refractive Flaw Requires it (Part 4)