Neurolens Convergence Insufficiency Study

Inclusion Criteria: * Male or female, and between 18-60 years of age at the time of signing the informed consent. * Best Corrected distance and near acuity are equal to or better than 20/25 Snellen Equivalent in each eye. * Best Corrected distance and near binocular acuity are equal to or better than 20/25 Snellen Equivalent. * Symptomatic as indicated by the CISS questionnaire (Score equal to or greater than 16) * Updated distance spectacle prescription must match the following 1. Spherical power inclusive between +4.00D to -8.00D 2. Cylinder power no more than -4.00Dcyl 3. ADD power i. Subgroup 1: No ADD ii. Subgroup2: minimum +1.00D ADD * Subjects' eye alignment tests must match the following: a. Successful measurement on the neurolens Measurement Device (Acceptable MQI and a numerical neurolens Value, no Low MQI or Convergence Excess) * Near point of convergence greater than or equal to 5cms * Capable of committing to the duration of the study. * Willing to comply with study procedures Exclusion Criteria: * Subjects who need a vertical prism. * Previously has worn neurolenses. * Subjects who need a near add less than 1.00D * Use of contact lenses during the study * Lack of binocular vision, including strabismus, amblyopia, or suppression. * Greater than 20 prism diopter of eye misalignment. * Aniseikonia greater than 3.00D spherical equivalent difference between eyes * Prior ocular surgery that in the estimation of the practitioner induces corneal scarring (RK, Corneal Transplant, etc.) or prior surgery involving the extraocular muscles (strabismus surgery). Surgeries that do not affect these parameters such as LASIK, PRK, or pterygium surgery are allowed. * Anterior segment conditions that could obfuscate or obscure reflections from the cornea, or reduce visual acuity, including but not limited to corneal scarring, large pinguecula, pterygium, keratoconus, dermatochalasis, ptosis, exophthalmos or cataract. * Clinical dry eye (defined as tear break-up time of less than 5 seconds) * Intraocular pressures greater than 25 mmHg in either eye or uncontrolled glaucoma * Macular disease, or any posterior segment finding which in the opinion of the investigator is visually and/or clinically significant * Change in acute or prophylactic migraine treatment medication or dosage within the previous two months. * Diabetes with ocular manifestation * Previous head or neck trauma (for instance, car accident, etc.) requiring medical intervention. * Open lesions or sores around the chin or eyes that will make contact with the device and may be subject to contraction or spread of infection. * Physical tremors or muscle spasms that prevent a subject from sitting still. * A history of seizures or seizure disorder. * Women who are pregnant or lactating at the time of the study entry * Mental incapacity that prevents a subject from being able to follow simple instructions such as "look at the target."