A method of treating meibomian gland dysfunction is disclosed. The method includes directing RF energy to an internal portion of a meibomian gland, selectively targeting an obstruction within a duct of the meibomian gland with the applied RF energy to melt, loosen, or soften the obstruction, and expressing the obstruction from the duct of the meibomian gland. An apparatus for treating meibomian gland dysfunction is also disclosed. The apparatus comprises at least one RF electrode configured to direct RF energy to an internal portion of a meibomian gland located in an eyelid of an eye, the at least one RF electrode further configured to selectively target an obstruction within a duct of the meibomian gland with the applied RF energy to melt, loosen, or soften the obstruction. The apparatus also comprises at least one expressor configured to express the obstruction from the duct of the meibomian gland.

Processes for sensing a variety of toxic chemicals and/or processes for determining the residual life of a filter or filtration system are provided. Exemplary process for sensing a toxic chemical include contacting a toxic chemical, or byproduct thereof, with a sorbent that includes a porous metal hydroxide and a transition metal reactant suitable to react with a toxic chemical or byproduct thereof. The sorbent is contacted with the toxic chemical or byproduct thereof for a sampling time. A difference between a post-exposure colorimetric state of the sorbent and a pre-exposure colorimetric state of the sorbent or control is determined to thereby sense exposure to, or the presence of, the toxic chemical or byproduct thereof.

Processes for sensing a variety of toxic chemicals and/or processes for determining the residual life of a filter or filtration system are provided. Exemplary process for sensing a toxic chemical include contacting a toxic chemical, or byproduct thereof, with a sorbent that includes a porous metal hydroxide and a transition metal reactant suitable to react with a toxic chemical or byproduct thereof. The sorbent is contacted with the toxic chemical or byproduct thereof for a sampling time. A difference between a post-exposure colorimetric state of the sorbent and a pre-exposure colorimetric state of the sorbent or control is determined to thereby sense exposure to, or the presence of, the toxic chemical or byproduct thereof.

A method of treating meibomian gland dysfunction is disclosed. The method includes directing RF energy to an internal portion of a meibomian gland, selectively targeting an obstruction within a duct of the meibomian gland with the applied RF energy to melt, loosen, or soften the obstruction, and expressing the obstruction from the duct of the meibomian gland. An apparatus for treating meibomian gland dysfunction is also disclosed. The apparatus comprises at least one RF electrode configured to direct RF energy to an internal portion of a meibomian gland located in an eyelid of an eye, the at least one RF electrode further configured to selectively target an obstruction within a duct of the meibomian gland with the applied RF energy to melt, loosen, or soften the obstruction. The apparatus also comprises at least one expressor configured to express the obstruction from the duct of the meibomian gland.