Our Achievement

The maximal capacity of tear production by lacrimal glands is a critical parameter to predict the evolution of DED. The individual maximal tear capacity of Dry Eye patients cannot be easily explored by eye health professionals.

i-Onion™ is an instrument that stimulates safely maximal tear secretion in an easy, brief and reliable manner.


Under resting conditions, a moist and lubricated eye surface is maintained through the continuous basal secretion of tears by the lacrimal glands. Rapid adjustments of tear’s production by the lacrimal glands in response to varying environmental conditions or potentially injurious challenges threatening the integrity of exposed eye tissues (cornea and conjunctiva), are obtained through peripheral nerve reflexes. These mediate the critical compensatory responses to environmental stresses (atmospheric dryness, dust, extreme temperatures, toxic gases or liquids in the air, foreign bodies) menacing the eyes of terrestrial animals.


Disorders leading to reduced eye surface wetness affects 10-20% of the world population. However, the traditional procedures hitherto used for a rapid and simple assessment of the lacrimal production in normal or pathological conditions are rough and limited in the daily clinical practice to the measurement of basal tear secretion by the lacrimal gland at rest using the Schirmer test. This approach does not provide any clue on how far the measured basal tear flow value is from the maximal secretory capacity of the lacrimal glands, neither detects whether the gland still possesses a tearing reserve volume large enough to supply the tear flow required. This is critical information to decide the use drugs (secretagogues) that activate lacrimal gland’s secretion.


i-Onion™: A new Way

An instrument that stimulates safely maximal tear secretion.
The i-ONION instrument is a brand-new ophthalmological device conceived and de built up by Tearful SL, that allows to obtain a quantitative evaluation of the maximal tear secretion capacity of the lacrimal glands in human and other mammal’s eyes in healthy or pathological conditions. To obtain this result, the i-Onion instrument releases a 3-second, 200ml/min, 99.9% medical grade CO2 gas jet onto the surface of the explored eye, producing a total excitation of the corneo-scleral nerve terminals mediating reflex secretion, thereby causing a controlled, transient maximal reflex production of tears by the lacrimal glands. The volume of tears produced by the stimulus impinging on the cornea of the explored subject, can be measured by qualified health personnel, using Schirmer test strips or any other ophthalmic technique used for tear flow measurement.

marzo 1, 2023

Recent Papers: The Ocular Surface

Purpose: To measure, the tear flow changes evoked in healthy subjects and dry eye disease (DED) patients by controlled sensory stimulation of the eye surface with i-Onion™, a new stimulation device.