Apparatus and method for photolithographically forming an ophthalmic lens

Method for photolithographically forming an ophthalmic lens (L), in particular a contact lens such as a soft contact lens, for example a silicone hydrogel contact lens, the method comprising:

• a) providing an apparatus (1) according to any one of the preceding claims;
• b) dispensing an uncured lens-forming material (3) into the container (2);
• c) moving the piston (4) along the second longitudinal axis (402) towards the container bottom (20) until a cavity (301) filled with a first layer of the uncured lens-forming material (3) is formed between the convex portion (401) of the distal piston end face (400) and the concave portion (201) of the inner surface (200) of the container bottom (20), the first layer of the uncured lens-forming material (3) having a thickness less than the thickness of the ophthalmic lens (L) to be formed;
• d) controlling the mask (6) with the aid of the control unit (7) in a manner so as to allow light to pass through the mask (6) to cure the first layer of the uncured lens-forming material contained in the cavity to form a cured first layer (L1) of the ophthalmic lens (L);
• e) moving the piston (4) along the second longitudinal axis (402) away from the container bottom (20), with the cured first layer (L1) of the ophthalmic lens adhered to the convex portion (401) of the distal piston end face (400), thus allowing the uncured lens-forming material (3) to flow into a space (302) between the cured first layer (L1) of the ophthalmic lens adhered to the convex portion (401) of the distal piston end face (400) and the container bottom (20);
• f) moving the piston (4) along the second longitudinal axis (402) towards the container bottom (20) until a further layer of uncured lens-forming material (3) is enclosed between the cured first layer (L1) of the ophthalmic lens adhered to the convex portion (401) of the distal piston end face (400) and the concave portion (201) of the inner surface (200) of the container bottom (20);
• g) controlling the mask (6) with the aid of the control unit (7) in a manner so as to allow light to pass through the mask (6) to at least partially cure the further layer of the uncured lens-forming material contained in the space to form a cured further layer (L2, L3, L4) of the ophthalmic lens;
• h) moving the piston (4) along the second longitudinal axis (402) away from the container bottom (20), with the cured first layer (L1) and the cured further layer (L2, L3, L4) of the ophthalmic lens adhered to the convex portion (401) of the distal piston end face (400), thus allowing the uncured lens-forming material (3) to flow into the space between the cured further layer (L2, L3, L4) of the ophthalmic lens and the concave portion (201) of the inner surface (200) of the container bottom (20);
• and
• i) repeating steps f) to h) until the ophthalmic lens (L) is formed.