the preferred and other embodiments of the present invention will now be further described . although the invention will be illustratively described hereinafter with reference to an herbal nutraceutical formulation comprising an aqueous extract of a particular plant species , it should be understood that the invention is not limited to aqueous extracts , but extends to formulations ( and to methods utilizing them ) that are prepared using other available extraction techniques , provided that each one yields the active components which are present in the plant species and that exhibit the salutary bio - efficacious properties of the present invention as disclosed herein . the present invention resides in the surprising finding that an extract of the plant capraria biflora can be formulated into compositions that are useful for preventing the formation of senile cataracts , or for treating such cataracts , especially by slowing their progression , in animals , including humans . capraria biflora is an evergreen shrub that ranges from the southern united states though central america and the carribean to bolivia in south america . the plant , the formal name of which is capraria biflora l ., is a member of the family scrophulariaceae , and is also known variously as capraria lanceolata , goat weed , wild tea , savadilla , té del pais , thé du pay , ditay paye and balsaminha . indigenous groups in south and central america have used the leaves of capraria biflora as an analgesic , anti - inflammatory , anti - pyretic , anti - arthritic , as well as for relief of gastrointestinal disturbances , to treat hemorrhoids and to treat ophthalmia ( inflammation of the eye ). however , prior to the development of the present invention , no use of any of the tissues of capraria biflora , or of any extract thereof , to reduce or eliminate the lens opacity that typifies any type of cataract , has ever been recorded . a naphthoquinone compound ( 6 , 9 - dimethyl - 3 -( 4 - methyl - 3 - pentenyl ) naphtho [ 1 , 8 - bc ]- pyran - 7 , 8 - dione ), designated biflorin , has been isolated from the leaves and roots of capraria biflora , and this compound has been shown to have some antimicrobial and cytotoxic activity against tumor cells . other compounds which have been isolated from the leaves of c . biflora include 2 , 4a , 5 , 8a - tetramethyl - 1 , 2 , 3 , 4 , 4a , 7 , 8 , 8a - octahydronaphthalen - 1 - ol , and 2 - isopropyl - 5 , 5 - dimethylcyclohex - 2 - enone . however , research conducted thus far has not revealed whether any of the specific compounds mentioned in this paragraph is responsible for , contributes to , or even plays some role in , the bio - efficacious activity exhibited by the invention as disclosed herein . in a preliminary in - vivo experiment conducted by applicant , which will be described in further detail hereinafter , it was discovered that an extract of capraria biflora was useful in ameliorating the effects of cataracts in an animal , specifically , a canine . it was initially thought that such an extract would be useful in preventing and / or treating all classes of cataracts , in humans as well as in other animals , but further in - vivo experiments with rats , in which diabetic cataracts had been induced , showed that such extracts were not useful in preventing and / or treating the diabetic cataracts in such rats , indicating that such extracts probably would probably not be useful in treating diabetic cataracts in other mammals either . still later in - vivo experiments with human patients , also to be described below , showed that such extracts were useful in preventing and / or treating senile cataracts , from which the canine patient had undoubtedly suffered as well . thus , while at present this invention finds use in the prevention and / or treatment of senile cataracts , further research may reveal that such extracts may be useful in treating non - senile , non - diabetic cataracts , such as steroid - induced cataracts or cataracts induced by exposure to chemicals or to radiation . in a preferred embodiment of the invention , an extract is prepared from the leaves of capraria biflora , as described in further detail below . the extract may be prepared from such leaves in intact form , or the leaves may first be ground or otherwise processed to maximize the efficiency of the extraction process . in alternative embodiments , other parts of the capraria biflora plant , including its flowers , roots , stems , stalks , twigs and / or seeds , may be used in preparing the extract , as it is believed that whatever the active components may be , which are present in the leaves of the plant and which exhibit the salutary properties of the present invention , may be found in the other vegetative and reproductive organs of the plant as well . in one embodiment of the invention , the extract is prepared by a conventional aqueous extraction method , that is , by mixing the leaves of capraria biflora with hot or boiling water . specifically , the aqueous solution is prepared as follows : eight ( 8 ) leaves of c . biflora are cut into small pieces and are placed into a 3 - ounce cup , and a balanced salt ( aqueous sodium chloride ) solution , having a temperature in the range of 70 ° c .- 120 ° c ., is poured over them . benzaikoniurn chloride ( also known as alkyldimethylbenzylammonium chloride ) is then added as a preservative , and the solution is allowed to stand for two ( 2 ) days in a refrigerator . the leaves are then removed , and the remaining liquid , constituting the aqueous extract , may then be used in accordance with the invention , although it is expected that the aqueous extract will have maximum potency immediately after its preparation , and that the effectiveness of the aqueous extract will diminish over time . if the aqueous extract is to be used directly , for topical instillation into the eye in liquid form , that is , as eye drops , then the extract solution should be shaken prior to use . although as set forth above the leaves may be mixed with the water directly , they may alternatively first be placed in a water - permeable bag , so as to facilitate removal of the spent leaves from the extract solution thereafter . in other embodiments of the invention , the aqueous extract may be concentrated by conventional methods before further use is made of it in accordance with the invention . in still other embodiments , capraria biflora or its aqueous extract is extracted with an organic solvent to further separate the active components from non - active components . such solvents may include alcohols such as methanol , ethanol or isopropanol , ketones such as acetone or methyl - ethyl ketone , esters such as ethyl acetate or butyl acetate , halogenated solvents such as methylene chloride or chloroform or hydrocarbon solvents such as hexane or toluene . in yet other embodiments , the individual components of the extract may be isolated using conventional chromatographic techniques upon conventional supports such as silica , alumina , size - exclusion and ion - exchange resins . in further embodiments , the individual components of the extract may be separated using distillation , crystallization and / or chemical derivatization . such techniques are well known to those having skill in the chemical arts . the nutraceutical compositions of the present invention can be formulated for prophylactic and / or therapeutic administration by various methods that are well known in the ophthalmic arts , maintaining required sterility and osmolarity . for example , in another embodiment , the aqueous extract , its concentrate or purified components thereof may be mixed with conventional pharmaceutically acceptable excipients designed to increase the stability of the extract , or of its concentrate or its purified components , so as to facilitate application to the eye , or to prolong the residence of the extract , its concentrate or its purified components upon the ocular surface . such excipients are well known to those having skill in the ophthalmic arts . the extract , its concentrate or its purified components may be applied in conventional pharmaceutically acceptable vehicles such as a solution . as indicated above , topical instillation in the eye is the preferred method of administration , most preferably in the form of liquid eye drops , although in addition to the alternative embodiment mentioned above of being administered topically combined with an ophthalmic ointment or lubricant , the aqueous extract , its concentrate or purified components thereof can also alternatively be administered by being adsorbed into a soft contact lens ( e . g ., that marketed by johnson & amp ; johnson under the trade name “ accuvue advance ”) or a dissolvable collagen corneal shield . the nutracuetical compositions of the present invention can alternatively be administered either systemically or by intraocular means , although at present these administration routes are less preferred . regarding systemic administration , that is , oral or parenteral administration , the aqueous extract , its concentrate or purified components thereof may be incorporated into tablets , pills , capsules , etc ., wherein the extract , its concentrate or purified components thereof is / are dispersed in one or more pharmaceutically acceptable , preferably biodegradable , carriers , and wherein the delivery system may also include one or more of the following : binders , excipients , lubricants , glidants and / or sweetening agents . regarding intraocular administration , that is , direct infusion into the eyeball , the aqueous extract , its concentrate or purified components thereof can be administered via injection , or by other delivery routes known in the ophthalmic arts that are applicable to administer a drug to the eye . these administration routes can be advantageous when direct treatment of the ocular lens , or the provision of a continuous supply of the aqueous extract , its concentrate or purified components thereof to the eye may be required . however , as it is expected that discontinuous treatment over time will be the most effective form of therapy , and since , at least for human patients , a non - invasive administration method that also admits of self - administration may be preferable , preparations which can be administered topically , particularly as liquid eye drops using a conventional eye dropper , are most preferred . when administered in that form , as a non - concentrated aqueous extract of capraria biflora which has not been further purified or further extracted with any organic solvents , the preferred dosage is one drop ( equivalent to 50 μl ) in each affected eye , three times per day , over the course of four to six weeks . it has been found that for such a dosage regimen , the aqueous extract should be replaced with a freshly - prepared aliquot at least once every two weeks , and that any remaining unused extract in the previous aliquot should not be used . it is also preferable that each aliquot of the aqueous extract be kept refrigerated when not in use . the following working examples illustrate both the manner in which such an aqueous extract of capraria biflora in accordance with the present invention has been used in both human and animal subjects suffering from at least one senile cataract , and the experimental results obtained , which demonstrate the efficacy of the invention . an elderly male animal , specifically a canine of the dachshund breed , aged 16 years , was observed as having chronically irritated , red eyes which made him visibly uncomfortable , and also as having greatly impaired vision due to cataracts . the impairment of his vision was deduced empirically from his behavior : the subject was observed bumping into walls and being unable to find his toys , as well as being unable to find his food , except by using his sense of smell . an ophthalmologic examination of the animal confirmed the presence of very dense cataracts in both eyes . an aqueous extract of c . biflora was prepared and was placed in an eye dropper ; this extract was prepared in accordance with the invention , except that only five leaves of c . biflora were used , no preservative was added , and instead of cooling the extract by refrigeration , it was allowed to stand at room temperature until it cooled . one drop was administered to each eye of the canine subject , three times per day , for about one week at a time , which resulted in a reduction in the observed eye redness and eye irritation , as well as an increase in the subject &# 39 ; s comfort with his eyes . the administration of the extract was interrupted on several occasions , upon which the irritation in the subject &# 39 ; s eyes returned within one or two days , but when the administration of the extract was thereafter resumed , the irritation was observed to decrease once again . after administration of the extract continued without interruption for three weeks , it was observed that the canine subject &# 39 ; s vision had improved as well . this was deduced empirically from the animal &# 39 ; s behavior : he ceased bumping into walls , found his toys and his food more easily , and could navigate generally without any observed visual impairment , from which it was concluded that the administration of the extract had reduced the cataracts from which the animal had suffered . a 78 - year old caucasian female with a 20 / 60 senile cataract in the right eye and a 20 / 30 senile cataract in the left eye underwent a full ophthalmological examination , which revealed no pathology in either eye except for the cataracts . a picture was taken of the right eye at this time . an aqueous extract of c . biflora was prepared in accordance with the invention , was placed in an eye dropper , and was given to the patient , who thereafter self - administered one drop three times a day , seven days a week , for three weeks , without missing a single dose , but only in the right eye . the patient was given , and thereafter used , a freshly - prepared aliquot of the aqueous extract once per week , and each aliquot was kept refrigerated when not in use . another ophthalmological examination was conducted three weeks after the first administration of the extract . the vision in the right eye had improved to 20 / 30 , and upon visual inspection the cataract appeared noticeably clearer . the remainder of the opthalmological examination was within normal limits . another picture of the cataract in the right eye was taken at this time for purposes of comparison . the patient reported that she “ could see again ” and could perform all of her normal daily activities . administration of the extract was therefore discontinued . an 81 - year old caucasian female , who had 20 / 60 - vision in both eyes due to senile cataracts , underwent a full opthalmological examination and no pathology was found in either eye except for the cataracts . pictures were taken of both cataracts at this time . an aqueous extract of c . biflora was prepared in accordance with the invention , was placed in an eye dropper , and was given to the patient , who thereafter self - administered one drop in each eye three times a day , seven days a week , for four weeks , without missing a single dose . the patient was given , and thereafter used , a freshly - prepared aliquot of the aqueous extract once per week , and each aliquot was kept refrigerated when not in use . another opthalmological examination was conducted four weeks after the first administration of the extract . the vision in the both eyes had improved to 20 / 30 , and upon visual inspection the cataracts appeared noticeably clearer . the remainder of the opthalmological examination was within normal limits . the patient reported that she could now read the newspaper again , something she hadn &# 39 ; t been able to do for five years . based on the experimental results summarized above , it is believed that the present invention comprises treatment methods and compositions that can ameliorate the effects , and / or inhibit the development , of senile cataracts in an animal subject , for example , a dog , a cat , a horse , a cow , a mouse , a rat or a human . as to human subjects in particular , it should be understood that , when used prophylactically , although any patient in a demographic group at significant risk for senile cataracts can be treated ( for example , humans over the age of 50 ), subjects can also be selected using more specific criteria . for example , patients who have biomicroscopic clinical evidence of an incipient senile cataract , or patients who have biomicroscopic evidence of a senile cataract combined with a decrease in visual acuity , can be selected for treatment . the present invention is useful in the treatment and / or prophylaxis of senile cataracts , and therefore finds industrial applicability in human and veterinary medicine . while there has been described what are at present considered to be the preferred embodiments of the present invention , it will be apparent to those skilled in the art that the embodiments described herein are by way of illustration and not of limitation . therefore , it is to be understood that various changes and modifications may be made in the embodiments disclosed herein without departing from the true spirit and scope of the present invention , as set forth in the appended claims .