fig1 illustrates ocular structures in cross - section , which provide a suitable environment for using the present assemblies and methods . a front surface of an eye is a cornea 101 . located behind the cornea 101 is an anterior chamber or aqueous chamber 102 . this is the primary reservoir of aqueous humor inside the eye . located behind the anterior chamber 102 is a lens 103 , and behind and around the lens 103 are ciliary processes 105 . the ciliary processes 105 are areas of the eye where aqueous humor is produced . the ciliary muscle 104 is roughly in the same plane as the lens 103 and is positioned around the perimeter of the lens 103 . a trabecular meshwork 106 , schlemm &# 39 ; s canal , and anterior ciliary veins are all located below the anterior chamber 102 at the bottom of the cornea 101 . this is the primary pathway for aqueous humor to exit the eye . behind the lens 103 and the ciliary processes 105 is the posterior chamber of the eye filled with viscous humor 108 . the viscous humor 108 is distinct from the aqueous humor , but the separation between the chambers holding such fluids is elastic and , as such , the pressures of the two different humor fluids are equal or approximately equal . an optic nerve 107 connects to the back of the eye . a lamina cribrosa 111 is the membrane over the junction of the optic nerve 107 and the eye . cerebrospinal fluid 109 baths the optic nerve 107 behind the lamina cribrosa 111 so that the lamina cribrosa is impacted on one side by the cerebrospinal fluid 109 pressure and on the other by the iop . during normal function of an eye , aqueous humor is produced inside the eye by the ciliary processes 105 in an anterior segment of the eye . as aqueous humor is steadily produced , a like amount of fluid must exit from the anterior chamber 102 of the eye to maintain a balanced eye pressure . the aqueous humor can exit the anterior chamber 102 by one or both of two main pathways . some is reabsorbed by the uveoscleral outflow tract around the ciliary muscles 104 . some exits the eye though the trabecular meshwork 106 , a porous region in the front of the eye located between the cornea 101 and iris insertion . the aqueous fluid that exits via the trabecular meshwork flows through schlemm &# 39 ; s canal into the anterior ciliary veins . the present assemblies and methods can modify the iop in a patient &# 39 ; s one or both eyes by altering the flow rate of aqueous humor across the trabecular meshwork 106 , schlemm &# 39 ; s canal , and the anterior ciliary vein pathway . fig2 illustrates a side schematic view of an assembly , as constructed in accordance with at least one embodiment , positioned in front of an eye . the assembly can include a goggle or goggles 120 , shown in cross - section , including one or more cavities 122 . the body of the goggle or goggles 120 can be relatively rigid and made of an impermeable clear plastic so that it can maintain the differential pressure inside the goggle or goggles , while allowing a patient wearing the goggle or goggles to see outward . there can be a seal material 121 positioned around a perimeter of the goggle body , which can create a seal between edges of the goggle or goggles and the patient &# 39 ; s skin around the eyes . the seal material can be a softer rubber or plastic wiper held in close contact with the skin by a strap around the head ( not shown ). the seal material can alternatively be made of a compressible foam material , for example . the cavity area 122 inside the goggle or goggles 120 can have its air pressure altered by components of the assembly . the eye lid 110 is shown over the front of the eye . it can be seen in the schematic illustration of fig2 that the altered air pressure in the cavity area 122 can act on the entire area in front of the eye . this altered pressure can be a reduced air pressure for patients with glaucoma or high iop so that it acts to decrease the iop . the altered pressure can be an increased air pressure for patients with optic disk edema ( swelling of the lamina cribrosa — see closing notes , below ). the assembly can also be configured to allow the altered pressure to be varied over time to different target levels if such configuration is found to be clinically desirable . bench testing utilizing the aforementioned techniques was conducted to investigate an effect on iop of a vacuum applied to a convex surface of a human cadaver eye . the experimental model involved mounting a front half of an incised eye to an inside surface of a pressure vessel . a seal was created between a perimeter of the incision and a surface of the pressure vessel so that the inside of the incised eye could be pressurized to a specified pressure or flow rate to simulate iop . the pressure vessel was then sealed , the initial iop recorded , and vacuum steps of 10 and 20 mmhg applied to the control volume above the convex surface of the incised eye . the final iop resulting from each vacuum step was then recorded . note that the lens of the incised eye had been removed and , while the trabecular meshwork was intact and functional , the urio scleral pathway and scleral muscles were not functional . two bench tests using this experimental model were conducted . in a first test , an initial iop of 24 . 3 mmhg was reduced to 19 . 3 mmhg and 9 . 1 mmhg for applied vacuums of 10 mmhg and 20 mmhg , respectively , returning to 28 . 3 mmhg upon release of the vacuum . in a second test , an initial iop of 28 . 3 mmhg was reduced to 19 . 4 mmhg and 10 . 4 mmhg for applied vacuums of 10 mmhg and 20 mmhg , respectively , returning to 28 . 9 mmhg upon release of the vacuum . fig3 illustrates an isometric view of an assembly in which a pressure control mechanism is mounted to a pair of goggles . the pressure control mechanism can include a pressure / vacuum pump 130 . this pump 130 can be a compressor , a vacuum pump , or configured to be reversible so that the same goggles can be used for either raising or lowering the pressure inside goggle cavities . the pressure / vacuum pump 130 can be in fluid communication with the inside of the goggles through one or more pressure tubes 131 . power for the pressure / vacuum pump 130 can be supplied by a battery pack 132 . the pressure / vacuum pump can be actuated by means of an on / off switch 134 . a set point or rage for the target pressure can be set by means of an adjustable dial 133 . the adjustable pressure set point or range can control the pressure in a closed loop manner when a pressure sensor monitoring the pressure in the goggle cavities is used . other means in which the adjustable pressure set point or range can be maintained include controlling a speed of the pump 130 or controlling a vent in the assembly so that only a portion of the fixed speed pump is acting on the area inside the goggle cavities . fig4 illustrates an isometric view of an assembly in which a pressure control mechanism is mounted remote to the goggles . a pressure / vacuum pump 140 can be set on a side table and plugged into a wall socket for power while the patient is sleeping or otherwise sedentary . the pressure / vacuum pump 140 can also be clipped to a belt and powered with a battery pack if the patient desires to be mobile . in the illustrated example , a pressure sensor 141 and a pressure control box 142 are shown . the pressure control box 142 can include the same or similar options of control as described in association with fig3 . the pressure sensor 141 can be used if the control method used is closed loop based on a monitored pressure . optionally , the pressure control target set point or range can be varied by the pressure control box 142 in response to a signal sent from another sensor monitoring the patient &# 39 ; s iop and / or csf pressure or surrogates for one or both pressures . in this way , the pressure inside the goggle cavities can be controlled to yield a targeted iop based on real time measurement of the iop or csf pressure . to further describe the present assemblies and methods , a non - limiting list of examples is provided here : in example 1 , an assembly can comprise a goggle , a pump , and a control mechanism . the goggle can include at least one cavity and can be configured to surround and be spaced from an eye . the pump can be in fluid communication with the at least one cavity . the control mechanism can be operatively coupled to the pump , and can be configured to receive a target pressure setting and maintain the target pressure in the at least one cavity through activation or deactivation of the pump . in example 2 , the assembly of example 1 can optionally be configured such that the goggle can include a set of goggles including a first cavity and a second cavity , the second cavity being spaced from the first cavity . in example 3 , the assembly of example 2 can optionally be configured such that the pump is in fluid communication with the first cavity and the second cavity . in example 4 , the assembly of any one or any combination of examples 1 - 3 can optionally be configured such that the pump includes one or both of a compressor device or a vacuum device . in example 5 , the assembly of any one or any combination of examples 1 - 4 can optionally further comprise at least one transducer configured to measure a pressure in the at least one cavity and electronically communicate the pressure to the control mechanism . in example 6 , the assembly of example 5 can optionally be configured such that the at least one transducer is a pressure sensor configured to monitor an intraocular pressure or a cerebrospinal fluid pressure . in example 7 , the assembly of any one or any combination of examples 1 - 6 can optionally be configured such that the control mechanism comprises a control circuit configured to initiate a therapy cycle to the at least one cavity based , in part , on the target pressure setting . in example 8 , the assembly of any one or any combination of examples 1 - 7 can optionally further comprise a battery configured to provide power to operate the pump and the control mechanism . in example 9 , the assembly of any one or any combination of examples 1 - 8 can optionally be configured such that the goggle includes one or more vents fluidly coupling the at least one cavity and a surrounding environment . in example 10 , the assembly of any one or any combination of examples 1 - 9 can optionally further comprise a seal member coupled to a perimeter of the goggle . in example 11 , a method can comprise placing an assembly , including a goggle having at least one cavity , a pump in fluid communication with the at least one cavity , and a control mechanism , over and around an eye , including spacing the goggle from a surface of the eye ; setting a target pressure within the at least one cavity using the control mechanism ; establishing the target pressure within the at least one cavity ; and maintaining the target pressure within the at least one cavity for a period of time . in example 12 , the method of example 11 can optionally further comprise adjusting the target pressure . in example 13 , the method of any one or any combination of examples 11 or 12 can optionally further comprise adjusting the target pressure based , at least in part , upon measurement of at least one physiological parameter . in example 14 , the method of any one or any combination of examples 11 - 13 can optionally be configured such that establishing the target pressure includes creating a pressure differential from atmospheric pressure in the at least one cavity . in example 15 , the method of example 14 can optionally be configured such that creating the pressure differential from atmospheric pressure in the at least one cavity includes changing a shape of the eye or changing a rate of drainage of an eye fluid through a trabecular meshwork associated with the eye . in example 16 , the method of any one or any combination of examples 11 - 15 can optionally be configured such that maintaining the target pressure includes delivering a predetermined therapeutic pressure cycle to the eye . in example 17 , the method of any one or any combination of examples 11 - 16 can optionally be configured such that maintaining the target pressure includes maintaining a pressure in an operating range from - 40 mmhg to 40 mmhg ( gage ). in example 18 , the method of example 17 can optionally be configured such that maintaining the pressure in the operating range includes maintaining the pressure in an operating range from 5 mmhg to 20 mmhg ( gage ). in example 19 , the method of any one or any combination of examples 11 - 18 can optionally be configured such that maintaining the target pressure includes reducing an intraocular pressure of the eye . in example 20 , the method of any one or any combination of examples 11 - 19 can optionally be configured such that maintaining the target pressure includes inhibiting a progression of glaucoma associated with the eye . 106 — trabecular meshwork , schlemm &# 39 ; s canal , anterior ciliary veins ( all in close proximity ) 130 — pressure and / or vacuum pump ( collectively referred to as a “ pump ”) 131 — one or more fluid lines connecting a pump to a goggle cavity area 133 — pressure adjusting control dial including a control circuit ( embodiment of “ control mechanism ”) 142 — pressure control box including a control circuit ( embodiment of “ control mechanism ”) high iop is a cause of glaucoma . recent studies are showing that there may be other causes of glaucoma in addition to iop . iop and other causes of glaucoma , including csf pressure and optic disc edema , are believed to be treatable using the present assemblies and methods . cerebrospinal fluid bathes the spinal cord , brain , and optic nerve . the optic nerve is surrounded by csf as it exits the intracranial vault and passes through the orbit and is present all the way up to the termination of the optic nerve as it enters the lamina cribrosa posterior in the eye . glaucoma occurs at the optic nerve in the lamina cribrosa . since csf bathes the optic nerve all the way to its entry in the eye , it is reasonable to conclude that both pressurized fluids , iop and csf , exposed to the optic nerve can contribute to glaucoma and can be treated using the present assemblies and methods . studies have shown that csf pressure is low in patients with glaucoma . the csf pressure is even lower in patients that have normal - tension glaucoma and is higher and potentially protective in people that have ocular hypertension . these findings are consistent with the findings seen in glaucomatous optic nerves where the optic nerve is bowed and the lamina cribrosa are bowed posterior . this is possibly caused by an iop that is higher than a csf pressure creating a net force on the lamina cribrosa that slowly remodels with time . it is also the opposite of what is seen in idiopathic intracranial hypertension where elevated csf pressure causes swelling and anterior bulging of the optic nerve . if further testing shows that csf is in fact a significant risk factor for glaucoma in concert with iop , then there can be a need for a glaucoma treatment similar to the present assemblies and methods that can be titrated to an appropriate level based on these two anatomic pressures for a patient . another condition effecting vision and related to these same anatomic pressures is optic disk edema or swelling . it is to be expected that the csf pressure at the level of the eye can increase in a zero gravity environment as the eye is relatively high in the csf cavity ( spinal cord , brain , optic nerve ). in a gravity environment , the csf pressure is higher in the caudal portion of the spinal cord due to gravity ( analogous to pressure increasing as you go deeper under water ). in zero gravity , this effect is not present , resulting in a relatively higher csf pressure at the height of the optic nerve . optic disk edema also is seen in other patients possibly due to high csf pressure relative to iop . for these patients , there can be a need for a treatment such as the present assemblies and methods that enable increasing the iop to a targeted pressure relative to the csf pressure to return the patients to a normal differential pressure across the lamina cribrosa . the above detailed description includes references to the accompanying drawings , which form a part of the detailed description . the drawings show , by way of illustration , specific embodiments in which the present assemblies and methods can be practiced . these embodiments are also referred to herein as “ examples .” the above detailed description is intended to be illustrative , and not restrictive . for example , the above - described examples ( or one or more elements thereof ) can be used in combination with each other . other embodiments can be used , such as by one of ordinary skill in the art upon reviewing the above description ( e . g ., a goggle or goggles including a single cavity or goggles having distinct cavities for each eye ). also , various features or elements can be grouped together to streamline the disclosure . this should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim . rather , inventive subject matter can lie in less than all features of a particular disclosed embodiment . thus , the following claims are hereby incorporated into the detailed description , with each claim standing on its own as a separate embodiment . the scope of the invention should be determined with reference to the appended claims , along with the full scope of equivalents to which such claims are entitled . in this document , the terms “ a ” or “ an ” are used to include one or more than one , independent of any other instances or usages of “ at least one ” or “ one or more .” in this document , the term “ or ” is used to refer to a nonexclusive or , such that “ a or b ” includes “ a but not b ,” “ b but not a ,” and “ a and b ,” unless otherwise indicated . in this document , the terms “ about ” and “ approximately ” are used to refer to an amount that is nearly , almost , or in the vicinity of being equal to a stated amount . in the appended claims , the terms “ including ” and “ in which ” are used as the plain - english equivalents of the respective terms “ comprising ” and “ wherein .” also , in the following claims , the terms “ including ” and “ comprising ” are open - ended , that is , a system , kit , or method that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim . moreover , in the following claims , the terms “ first ,” “ second ,” and “ third ,” etc . are used merely as labels , and are not intended to impose numerical requirements on their objects . the abstract is provided to allow the reader to quickly ascertain the nature of the technical disclosure . it is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims .