PURPOSE: To assess the correlation between the change in pupil diameter, age and depth of the anterior chamber after 3 months of cataract surgery both in photopic and mesopic conditions. And study the changes of the pupillary diameter at 3 months after surgery in the two light conditions

Healthy patients who are going to be operated on for cataracts are expected to take part in the study. If during the clinical study the minimum number of patients established in the protocol is exceeded, new samples will continue to be registered until the end of the established period.

The sample selection mechanism is by consecutive recruitment during the study period (in order of arrival at the medical office). Patients are operated bilaterally in a period not exceeding 15 days and it will get the variables of both eyes. A simple random sampling will be used for the choice of single eye data per patient.

Inclusion Criteria:

• Both sexes with age equal to or greater than 45 years
• Diagnosed cataract N1, C1, P1 or worse in some eye.
• Patients who will be operated on both eyes.
• Patients who have not been diagnosed with diabetes mellitus.
• Patients who have given their informed consent to take part in the study.

Exclusion Criteria:

• Age under 45 years.
• Patients with anisocoria, neurological disorders, diagnosed with diabetes mellitus, glaucoma or another eye disease.
• Patients with complications during and after cataract surgery.

The field in which the study will be carried out is a private medical centre. TACIR Ophthalmology clinic is located in the TEKNON Medical Center in the city of Barcelona. The study population will be the patients of the TACIR ophthalmology clinic who will be operated on cataracts and agree to take part in the study.