Contact lens packaging

1. A stack of individually separable packages for a plurality of contact lenses, each individual lens being packaged between a first surface and a second surface,

wherein the first surface is provided by a first one of the individually separable packages and the second surface is provided by a second one of the individually separable packages,

wherein each package comprises: a concave cup-shaped portion which accommodates a contact lens and an aqueous liquid; and a peripheral portion; the packages being stacked such that the concave cup-shaped portion of one package is partially accommodated within the concave cup-shaped portion of an adjacent package, thereby reducing dead volume in the stack,

wherein adjacent members of the stack are sealed to one another by a mechanical sealing fit, and

wherein the packages comprise a frangible portion which is broken or ruptured if adjacent packages are separated, such that a tamper-evident seal is provided.

2. A stack according to claim 1 , wherein each of the plurality of packages is essentially identical.

3. A stack according to claim 1 , comprising a plurality of left-handed packages and a plurality of right-handed packages, the handedness optionally being conferred by the shape or position of a projecting flange portion.

4. A stack according to claim 1 , wherein the peripheral portion comprises a thin protruding flange portion, which projects outwardly and provides a surface to which a consumer may apply a suitable force to separate an individual package from the stack.

5. A stack according to claim 1 , in combination with a holder, said holder having a flat base portion and at least one upright member which defines a channel or groove which accommodates the stack.

6. A stack and holder combination according to claim 5 , wherein the upright member and flat base portion are integrally formed from a synthetic plastics material.

7. A stack and holder combination according to claim 5 , wherein the channel or groove accommodates two stacks of contact lens packages, side-by-side.

8. A stack and holder combination according to claim 5 , wherein the holder comprises dispensing means, actuation of which serves to separate an individual contact lens package from the stack.

9. A stack and holder combination according to any one of claim 5 , wherein the holder comprises biasing means which tends to urge the stack out of the holder, and restraining means which resists the biasing means.

10. A method of making a stack of a plurality of individually separable contact lens packages, the method comprising the steps of:

(a) forming a plurality of empty individual contact lens packages, each package comprising a concave cup-shaped portion which accommodates a contact lens;

(b) inserting a contact lens and an aliquot of suitable aqueous liquid in a cavity in the concave cup-shaped portion of a first package; and

(c) sealing the contact lens and aqueous liquid in the cavity by positioning a second package on top of the first package, such that the concave cup-shaped portion of the second package is partially accommodated within the concave cup-shaped portion of the first package, and sealing the second package to the first,

wherein adjacent members of the stack are sealed to one another by a mechanical sealing fit, and

wherein the packages comprise a frangible portion which is broken or ruptured if adjacent packages are separated, such that a tamper-evident seal is provided.

11. A method according to claim 10 , in which steps (b) and (c) are repeated a plurality of times to build up the stack of packages.

12. A method according to claim 10 , further comprising the step of sterilising the packages by autoclaving.

13. A method according to claim 10 , wherein the stack of packages is sterilised during stack formation by UV irradiation.