The goal of this feasibility study is to learn more about the performance of the intraocular lens device, if the device is safe for use and what the best surgical techniques are for implanting the product in patients who require correction of aphakia following phacoemulsification extraction of a senile cataract. The main questions it aims to answer are:

• Will the patient have any related complications?
• Will a patient's vision improve after surgery?

Researchers will compare the eye treated with the investigational product with the eye treated with another product to see if there are any differences in vision and safety.

• Participants will be asked to attend all scheduled visits for the study, approximately 11 visits in total over 3 years.
• During these visits the participants will be asked about their medical history, have testing and measurements taken, and one visit that is the scheduled surgery.

The participants will be asked to use eye drops that have been prescribed by the doctor performing the surgery.

Inclusion Criteria:

• Adults who are at least 21 years of age or older and of legal age or capacity to consent.
• Scheduled to undergo primary intraocular lens implantation for the correction of aphakia following phacoemulsification extraction of a senile cataract.
• Clear intraocular media other than cataract.
• Potential visual acuity of 20/32 or better in both eyes after cataract removal and IOL implantation as determined by diagnostic testing or investigator's judgement.
• Preoperative corrected distance visual acuity (CDVA) worse than 20/40 either with or without a glare source present (e.g., Brightness Acuity Tester) or scheduled for cataract removal due to significant cataract-related symptoms/complaints.
• Calculated IOL power is within the range of the investigational IOL (+17.0 to +24.0 D).
• Less than or equal to 1.0 diopter (D) of preoperative keratometric astigmatism.
• In good general health at screening as determined by the investigator.
• Signed written informed consent.
• Availability, willingness, and sufficient cognitive awareness to comply with examination procedures and schedule.
• Operative Criteria -- For unilaterally implanted Adaptilens A-IOL Eyes: Completion of uncomplicated cataract surgery with implantation of the Control IOL and with no ongoing or persistent sight-threatening adverse events in the Control eye.

Exclusion Criteria:

• Planned secondary procedures (such as LASIK) during the term of the study; Nd YAG capsulotomy is permitted.
• Taking systemic medications that may confound the outcome or increase the risk to the subject.
• Ocular conditions that may predispose for future complications.
• Previous intraocular or corneal surgery that might confound the outcome of the investigation or increase the risk to the subject.
• Pregnant, lactating during the course of the investigation, or with another condition associated with fluctuation of hormones that could lead to refractive changes.
• Diagnosed degenerative visual disorders (e.g. macular degeneration or other retinal disorders) that are predicted to cause future CDVA loss worse than 20/40.
• Any anterior segment pathology (anterior segment or corneal abnormalities, chronic uveitis, iritis, corneal dystrophy, pseudoexfoliation, etc.).
• Glaucoma, glaucoma suspect or ocular hypertension, i.e., IOP > 22 mmHg.
• Previous retinal detachment or retinal pathology, including age-related macular degeneration.
• Diabetes, currently being treated systemically and with retinopathy.
• Systemic or ocular disease that may prevent the patient from achieving CDVA of 20/32 or better post operatively.
• Require chronic administration of any topical ophthalmic or systemic medication that may affect accommodation such as mydriatic, cycloplegic and myotic agents; tricyclic antidepressants, phenothiazines, benzodiazepines, first generation antihistamines, anticholinergic agents.
• CDVA of 20/32 or worse in the fellow eye not attributable to cataract.
• Current participation in, or have participated in, an investigational study, other than this study, within the previous 60 days before the operative day.
• Previous ocular surgery in the operative eye, including refractive surgery.