Updated AUG 29, 2022 • 7 min read
In a young and healthy eye, light travels unimpeded through clear ocular structures to then be focused on the light sensitive lining inside the eye known as the retina.
The first interaction of light with the eye is a tear layer on the surface of the cornea. Light continues through the cornea and a clear fluid known as aqueous before reaching the crystalline lens, which is located just behind the iris, the colored part of the eye. Between the crystalline lens and the retina is a clear gel-like fluid known as the vitreous body.
The crystalline lens (or, more simply, the lens) is a slightly flattened marble shaped structure responsible, in part, for helping to focus the eye. When the lens becomes cloudy, yellow and/or limits the amount of light that travels through it, it is known as a cataract.
When cataracts are present, vision becomes more difficult with symptoms of glare, haziness, cloudy or dim vision. Cataracts may occur throughout one’s life from birth through old age, and it is not unusual to have them after age 65.
According to the World Health Organization, cataracts are the leading cause of preventable blindness worldwide [1,2].
Most cataracts form slowly over time, so they are associated with aging. From the time of the eye’s lens formation, the lens continues to add layers of cells. These cells do not shed or slough off. Instead, as additional layers are created, the lens becomes more compact, increasing in size and density.
At birth the lens is soft and malleable but as density increases with time, it is no longer able to change shape.
Most people notice beginning in their 40s that it becomes increasingly more difficult to change focus from distance vision to reading distance. As the lens increases in density, the eye gradually loses its ability to change focus. Presbyopia refers to the eye not being able to change focus. (Hence the need for bifocals, reading glasses or longer arms!)
One function of the lens is the absorption of UV radiation. There is oxidative stress on the lens related to the absorption of UV radiation. However, by performing this function, the lens acts to protect the light-sensitive retina, especially the macula. The macula allows us to be able to see faces, read, and see details so important for quality vision.
Over time, lens metabolism, altered lens protein structure, UV radiation, and cumulative oxidative stress induces changes in the lens that lead to age-related cataract formation .
There are two common types of age-related cataracts which describe the location within the lens: nuclear and cortical.
After your doctor has diagnosed cataracts as the cause for vision loss, there are several considerations to take into account.
If the decision is to go forth with cataract removal, for the best surgical outcome, the ocular surface needs to be in good shape. The ocular surface and lids need to be evaluated and treated, if necessary.
It is important to address dry eye before surgery. Some of the recommendations may include: non-preserved artificial tears, warm compresses, topical steroid drops, topical cyclosporine A drops, punctal plugs, and oral nutritional supplements.
In preparation for cataract surgery, measurements are taken to decide the best intraocular lens (IOL) power to replace the cataractous lens. There are options for the type and design of the IOL. A monofocal lens will set clear vision at one distance. Frequently vision is set to be clear far away, and then reading glasses are used for close vision. There are multifocal IOL designs that function with the same intent as bifocals.
Another option is to set vision in one eye for distance vision and the other for close vision. To be sure that this option will be visually tolerated, a trial using contact lenses will help to demonstrate whether or not this will work.
Cataract surgery is performed in an outpatient facility or a hospital. After the surgery, a shield will be placed over the eye for protection. Often the eye will be evaluated one day post surgery, one week then one month. Follow the surgeon’s directions for post surgical drop instillation.
Typically these drops include an antibiotic, a steroid, and an NSAID. An eye shield is worn at night to help to keep the eye from being injured while sleeping. Avoid getting soap or water in the healing eye. The eyes should not be rubbed. Your doctor will advise when lifting, and exercise may begin again.
Removing cataracts can greatly enhance the quality of vision and life. Improved vision may even decrease the risk of falls and car accidents. One of the great benefits after cataract surgery today, is that clear distant and near vision without glasses is possible.
To decrease the risk of developing cataracts, use glasses and sunglasses that offer UV light protection appropriate for the situation, be it skiing, a day at the beach, or playing golf. Start UV protection in childhood. Also, a healthy diet that includes lots of colorful fruits, vegetables and cold water fish like salmon supports general eye wellness.
As with any surgery, there are inherent risks and possible complications. So, the decision to have cataract surgery should be well thought out and discussed with your doctor.
Our website services, content, and products are for informational purposes only. GlassesUSA.com does not provide medical advice, diagnosis or treatment. See additional information.