High water content ophthalmic devices

1. An ophthalmic device that is a polymerization product of a monomeric mixture comprising: (a) a major amount of a non-silicone-containing hydrophilic monomer; (b) a hydrophobic monomer; and (c) a crosslinking agent, wherein the ophthalmic device has an equilibrium water content of at least about 70 weight percent and further wherein the ophthalmic device has an evaporative dehydration barrier layer on the surface thereof.

2. The ophthalmic device of claim 1 , having an equilibrium water content of at least about 80 weight percent.

3. The ophthalmic device of claim 1 , wherein the non-silicone-containing hydrophilic monomer is selected from the group consisting of an amide, cyclic lactam, poly(alkene glycols) functionalized with polymerizable groups and mixtures thereof.

4. The ophthalmic device of claim 1 , wherein the non-silicone-containing hydrophilic monomer is selected from the group consisting of N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N-vinyl-2-pyrrolidone and mixtures thereof.

5. The ophthalmic device of claim 1 , wherein the non-silicone-containing hydrophilic monomer is present in the monomeric mixture in an amount of greater than about 70 weight percent, based on the total weight of the monomeric mixture.

6. The ophthalmic device of claim 1 , wherein the non-silicone-containing hydrophilic monomer is present in the monomeric mixture in an amount of greater than about 80 weight percent, based on the total weight of the monomeric mixture.

7. The ophthalmic device of claim 1 , wherein the hydrophobic monomer is represented by the structure of Formula I:

wherein R 1 is methyl or hydrogen; R 2 is —O— or —NH—; R 3 and R 4 are independently a divalent radical selected from the group consisting of —CH 2 —, —CHOH— and —CHR 6 —; R 5 and R 6 are independently a branched C 3 -C 8 alkyl group; and n is an integer of at least 1, and m and p are independently 0 or an integer of at least 1, provided that the sum of m, p and n is 2, 3, 4 or 5.

8. The ophthalmic device of claim 1 , wherein the hydrophobic monomer is present in the monomeric mixture in an amount of about 0.5 to about 25 weight percent.

9. The ophthalmic device of claim 1 , wherein the monomeric mixture further comprises a hydrophobic silicon-containing monomer.

10. The ophthalmic device of claim 9 , wherein the hydrophobic silicon-containing monomer is O-(methacryloxyethyl)-N-(triethoxysilylpropyl)urethane.

11. The ophthalmic device of claim 9 , wherein the hydrophobic silicon-containing monomer is present in the monomeric mixture in an amount up to about 15 weight percent.

12. The ophthalmic device of claim 1 , having a dehydration rate of less than or equal to about 0.600 mg/minute.

13. The ophthalmic device of claim 9 , having a dehydration rate of less than or equal to about 0.450 mg/minute.

14. The ophthalmic device of claim 1 , wherein the ophthalmic device is a contact lens.

15. An ophthalmic device that is a polymerization product of a monomeric mixture comprising: (a) a major amount of a non-silicone-containing hydrophilic monomer; (b) a hydrophobic monomer; and (c) a crosslinking agent, wherein the ophthalmic device has an equilibrium water content of at least about 70 weight percent and further wherein the ophthalmic device has a dehydration rate of less than or equal to about 0.600 mg/minute.

16. The ophthalmic device of claim 15 , having an equilibrium water content of at least about 80 weight percent.

17. The ophthalmic device of claim 15 , wherein the non-silicone-containing hydrophilic monomer is selected from the group consisting of an amide, cyclic lactam, poly(alkene glycols) functionalized with polymerizable groups and mixtures thereof.

18. The ophthalmic device of claim 15 , wherein the monomer mixture further comprises a silicone-containing hydrophobic monomer and further wherein the ophthalmic device has a dehydration rate of less than or equal to about 0.450 mg/minute.

19. A method comprising the step of casting a monomeric mixture comprising (a) a major amount of a non-silicone-containing hydrophilic monomer; (b) a hydrophobic monomer; and (c) a crosslinking agent in a hydrophobic substrate to form an ophthalmic device having an evaporative dehydration barrier layer on the surface thereof and wherein the ophthalmic device has an equilibrium water content of at least about 70 weight percent.

20. The method of claim 19 , wherein the ophthalmic device has an equilibrium water content of at least about 80 weight percent.

21. The method of claim 19 , wherein the ophthalmic device has a dehydration rate of less than or equal to about 0.600 mg/minute.

22. The method of claim 19 , wherein the hydrophilic monomer is present in the monomeric mixture in an amount of greater than about 70 weight percent.

23. The method of claim 19 , wherein the monomeric mixture further comprises a hydrophobic silicon-containing monomer.

24. The method of claim 19 , wherein the hydrophobic substrate comprises polypropylene, polystyrene, silanized glass or a combination thereof.

25. A method for substantially mitigating evaporative corneal dehydration associated with an ophthalmic device having an equilibrium water content of at least about 70 weight percent, the method comprising contacting the surface of an eye of a subject with an ophthalmic device that is a polymerization product of a monomeric mixture comprising: (a) a major amount of a non-silicone-containing hydrophilic monomer; (b) a hydrophobic monomer; and (c) a crosslinking agent, wherein the ophthalmic device has an equilibrium water content of at least about 70 weight percent and further wherein the ophthalmic device has a dehydration rate of less than or equal to about 0.600 mg/minute.