Disclaimers and Forward-Looking Statements This presentation and various remarks which may be made during this presentation contain forward-looking statements within the meaning of the Private Securities Litigation Refor

2017 Research and Development Day

October 10, 2017 Exhibit 99.1

Disclaimers and Forward-Looking

Statements This presentation and various remarks which may be made during this presentation contain forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 and Section 21E of the Securities Exchange Act

of 1934, as amended, including statements regarding Aldeyra's possible or assumed future results of operations, expenses and financing needs, business strategies and plans, research and development plans or expectations, trends, the structure,

timing and success of Aldeyra's planned or pending clinical trials, expected milestones, market sizing, pricing and reimbursement, competitive position, regulatory matters, industry environment and potential growth opportunities, among other

things. Forward-looking statements include all statements that are not historical facts and, in some cases, can be identified by terms such as "may," "might," "will," "objective," "intend,"

"should," "could," "can," "would," "expect," "believe," "anticipate," "project," "target," "design," "estimate,"

"predict," "potential," "plan" or similar expressions and the negatives of those terms. Forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause Aldeyra's

actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. These statements reflect Aldeyra's current views with respect

to future events and are based on assumptions and subject to risks and uncertainties, including the development and clinical plans for Aldeyra's product candidates and Aldeyra's continuing review and quality control analysis of clinical

data. Important factors that could cause actual results to differ materially from those reflected in Aldeyra's forward-looking statements are described in the "Risk Factors" and "Management's Discussion and Analysis of

Financial Condition and Results of Operations" sections of Aldeyra's Annual Report on Form 10-K for the year ended December 31, 2016 and Quarterly Report on Form 10-Q for the quarter ended June 30, 2017, which are on file with the

Securities and Exchange Commission (SEC) and available on the SEC's website at www.sec.gov. Additional factors may be described in those sections of Aldeyra's Quarterly Report on Form 10-Q for the quarter ended September 30, 2017, to be filed with

the SEC in the fourth quarter of 2017. In addition to the risks described above and in Aldeyra's other filings with the SEC, other unknown or unpredictable factors also could affect Aldeyra's results. No forward-looking statements can be guaranteed

and actual results may differ materially from such statements. The information in this presentation is provided only as of October 10, 2017, and Aldeyra undertakes no obligation to update any forward-looking statements contained in this presentation

on account of new information, future events, or otherwise, except as required by law.

Aldeyra Therapeutics 2017 Research and

Development Day New Results from Phase 2 Clinical Trials in Allergic Conjunctivitis and Dry Eye Disease David Clark, MD, Chief Medical Officer, Aldeyra Unmet Medical Need in Allergic Conjunctivitis and Dry Eye Disease Tim Surgenor, RedSky Partners,

LLC Clinical and Regulatory Opportunities in Dry Eye Disease Gary Novack , PhD, Visiting Professor of Pharmacology and Ophthalmology, University of California, Davis, School of Medicine The Intersection of Dry Eye Disease and Allergic

Conjunctivitis John Sheppard, MD, Professor of Ophthalmology at Eastern Virginia Medical School Introduction of ADX - 103 and the Retinal Disease Program Susan Macdonald, PhD, Vice President of Research and Development, Aldeyra

Clinically Important Response Results

from Phase 2b Clinical Trial in Allergic Conjunctivitis David Clark, MD Chief Medical Officer Aldeyra Therapeutics

Allergic Conjunctivitis Phase 2b

Clinical Design Groups Topical Ocular ADX-102 0.1%, ADX-102 0.5%, or Vehicle Randomization Double-Masked, Vehicle-Controlled 1:1:1 Enrollment 154 Patients with History of Allergic Conjunctivitis Model Single Dose Seasonal and Perennial Allergen

Challenge Endpoint Patient-Reported Itching Score (0 to 4) Further information can be found on www.clinicaltrials.gov: Trial #NCT03012165.

Histaminic and Aldehyde-Mediated Phases

After Allergen Challenge Histaminic Phase Aldehyde-Mediated Phase (Cells, cytokines, and other aldehyde-stimulated factors) In Phase 2 clinical trials, ADX-102 shown to be effective for aldehyde-mediated allergy, for which no drug is approved, and

which affects all allergic conjunctivitis patients. 0102030405060 Minutes Following Single Exposure to Allergen ADX-102 Activity Antihistamine Activity

The Activity of Antihistamines

Diminishes Rapidly as ADX-102 Activity Increases Data from olopatadine Summary Basis of Approval, ADX-102 Phase 2b clinical trial.

ADX-102 Decreased Ocular Itch in Phase

2b Clinical Trial ADX-102 was statistically superior to control in reducing allergic ocular itch 10 to 60 minutes after allergen challenge, when the activity of antihistamines diminishes.

ADX-102 Decreased Area Under the Curve

Ocular Itch Score in Phase 2b Clinical Trial Area under the curve indicated a durable effect of ADX-102 in reducing ocular itch score in a manner that is statistically superior to that of control 10 to 60 minutes after allergen challenge, when the

activity of antihistamines diminishes.

Probability of Clinically Important

Response Was Statistically Higher in ADX-102-Treated Patients One-point improvement in ocular itch score is US FDA regulatory precedent When a responder is defined as a patient that improves one point from peak baseline itch score, odds ratio

analysis indicated that ADX-102-treated patients were more than three times as likely to achieve clinical response (p=0.02 for each drug group) in the Phase 2b clinical trial Data from ADX-102 Phase 2b clinical trial.

Clinical Response Achieved Faster in

ADX-102 Group vs. the Vehicle Group 0.1% and 0.5% ADX-102 groups achieved statistically faster clinical response than vehicle (p=0.0006 and p=0.008, respectively). As an example, the graph to the right indicates that 94% of 0.1% ADX-102-treated

patients responded by 20 minutes post-challenge in the Phase 2a clinical trial. p values are subject to change based on quality control analysis. Data from ADX-102 Phase 2b clinical trial.

Allergic Conjunctivitis Phase 2b Key

Conclusions ADX-102 was shown to be statistically superior to vehicle in durably reducing ocular itch score from 10 to 60 minutes after exposure to allergen, an efficacy profile that has not been demonstrated for antihistamines. Relative to control,

the activity of ADX-102 increased during a period when the activity of antihistamines decreases. Using the US FDA regulatory precedent of one point improvement on the ocular itch score, the clinical response of drug-treated patients was

statistically superior to that of vehicle treated patients, when response is measured vs. peak baseline itch score. Using odds ratio analysis, ADX-102-treated patients were more than three times more likely to respond than vehicle-treated patients.

Time to response was statistically faster in ADX-102 treated patients vs. that of vehicle-treated patients.

Allergic Conjunctivitis Phase 3

Clinical Design Groups Topical Ocular ADX-102 0.1%, ADX-102 0.5%, or Vehicle Randomization Double-Masked, Vehicle-Controlled 1:1:1 Enrollment 150 Patients with History of Allergic Conjunctivitis Model Single Dose Seasonal Allergen Challenge Endpoint

Patient-Reported Itching Score (0 to 4) *Pending additional non-clinical data and other factors, which may not be in Aldeyra's control

A Market-Based Analysis of Unmet

Medical Need in Allergic Conjunctivitis and Dry Eye Disease Tim Surgenor 617-584-2638 tsurgenor@redskyco.com Cambridge Innovation Center One Broadway, 4th Floor Cambridge, MA 02142 The opinions expressed herein are those of RedSky Partners, LLC and

do not necessarily reflect the views of Aldeyra.

Overview ADX-102, if approved, has

potential to be differentiated, branded entry in market for eye drop treatments ADX-102 appears to provide clinically significant improvement in phase 2 studies in multiple indications allergic conjunctivitis dry eye disease noninfectious anterior

uveitis Positioning as first line anti-inflammatory with unique mechanism and without steroid adverse events may convey significant market potential in anterior uveitis and dry eye disease In allergic conjunctivitis, positioning between short-acting

antihistamines and corticosteroids is differentiated and attractive to physicians

US Eye Drop Market in 2016 Source:

Emerging Value Proposition -

ADX-102 Noninfectious Anterior Uveitis Dry Eye Allergic Conjunctivitis Market Need ~150,000 US patients Treated with corticosteroids, which may lead to cataracts and glaucoma ~20 million patients Only two approved drugs Therapy generally considered

to be inadequate ~20% of US population ~60 million patients Antihistamines provide short term relief Off-label use of chronic corticosteroids represents safety risk ADX-102 Efficacy Profile Efficacy similar to corticosteroid monotherapy at 4 weeks

in Phase 2b trial Statistically significant improvement in multiple signs and symptoms at 4 weeks, with apparent rapid onset in Phase 2a trial Statistically significant reduction in itching at 10-60 minutes after challenge in Phase 2b trial Safety /

Tolerability to Date No observed increase in intraocular pressure No observed significant adverse events Favorable tolerability No observed significant adverse events Favorable tolerability No observed significant adverse events Dose being studied

0.5% 0.1%, 0.25% 0.1%, 0.5% Opportunity for lifecycle management and dose form opportunities Source: ALDX press releases

ADX-102 Opportunity in Allergic

Conjunctivitis Allergic conjunctivitis - inflammatory disease of conjunctiva resulting from allergen exposure Affects ~20% of US population with range of severity Mast-cell stabilizers or antihistamines provide short term relief -acute

phase allergic reaction (up to 20 minutes) Histamine release is acute; antihistamines work immediately following allergen exposure Activity of antihistamines diminishes rapidly Patients with chronic or severe forms of allergic conjunctivitis are

treated with topical corticosteroids - creating long-term risks of cataracts and glaucoma ADX-102 Hypothesis Aldehyde trap mechanism could be substantial market opportunity for patients with inadequate relief from antihistamines and who are

not candidates for corticosteroids

Survey Overview Survey of 75 US

Physicians Ophthalmology - 45 Optometry - 15 Allergy / Immunology - 15 Conducted in July 2017 on behalf of Aldeyra Active in treatment of allergic conjunctivitis Source: GLG market research

How do you currently treat your AC

patients with topical products? Source: GLG market research

For AC patients treated with topical

ophthalmic antihistamines, what percent apply to each category below? Source: GLG market research

Cross-sectional study of allergic

conjunctivitis consistent with survey results 2015 Study in Italy 2687 Allergic conjunctivitis patients 43% used OTC 29% used topical antihistamines 41% used corticosteroids 60% used multiple medications Source: Allergic conjunctivitis: a

cross-sectional study; A. Leonardi et al; Clinical & Experimental Allergy, 2015 (45) 1118-1125.

What percentage of your AC patients

on anti-histamines, after a single dose, fall into the following categories of symptom relief? Source: GLG market research

What percentage of your AC patients

have some type of mixed condition? Source: GLG market research

2011 Study of allergic

conjunctivitis patients and dry eye syndrome consistent with survey results M.M. Hom et al. / Ann Allergy Asthma Immunol 108 (2012) 163-166 Dry Eye Patients (Dryness) Allergic Conjunctivitis (Itch) 45% of Allergic Conjunctivitis Patients with

Itch Symptoms Also Experience Dryness

If a safe, non-steroidal,

anti-inflammatory product was available that provided a more sustained symptomatic response than antihistamines, what percent of your AC patients would be candidates for this therapy? Source: GLG market research

Conclusions - ADX-102 has

potential for differentiated profile in allergic conjunctivitis treatment ADX-102 has a novel therapeutic profile In Phase 2 clinical trials, the largest reduction in itching occured after typical antihistamine peak activity This observation

consistent with effect on aldehyde-mediated allergic response Potential for positioning as treatment for allergic conjunctivitis and dry eye Despite common perceptions, antihistamine treatment of allergic conjunctivitis has significant limitations

Antihistamines work acutely following allergen exposure Activity of antihistamines diminishes rapidly Physician survey showed large percentage of patients do not receive adequate therapy using antihistamines alone Limited duration, effectiveness

Large population moves on the corticosteroids Physician survey identified strong physician preference for product with ADX-102 therapeutic profile Potential to provide more sustained relief Potential to avoid patient exposure to side effects of

Additional Data on Aldehyde

Biomarker Correlation with Clinical Efficacy from Phase 2a Dry Eye Disease Clinical Trial David Clark, MD Chief Medical Officer Aldeyra Therapeutics

Dry Eye Disease Phase 2a Clinical

Design Groups Topical Ocular ADX-102 Formulations: 0.1% ADX-102 0.5% ADX-102 0.5% (Lipid) ADX-102 Randomization 1:1:1 28-Day Four-Times-Daily Dosing Enrollment 51 Patients with Dry Eye Disease Primary Objective Dose Selection for Phase 2b Based on

Tolerability and Exploratory Efficacy Endpoints Standard Dry Eye Disease Signs and Symptoms Further information can be found on www.clinicaltrials.gov: Trial #NCT03162783.

Statistically Significant

Improvement in Multiple Dry Eye Disease Signs and Symptoms Endpoint (Pooled Data) Pre-Treatment Post-Treatment p value* Symptom Assessment in Dry Eye (SANDE) Score 61 52 p = 0.003 Ocular Discomfort Score 2.3 1.5 p = 0.00002 Overall 4-Symptom Score

2.6 2.0 p = 0.0004 Tear Volume (Schirmer Test) 5.6 8.3 p = 0.008 Osmolarity 304 294 p = 0.003 Total Staining (Lissamine Green) 5.2 4.3 p = 0.002 p values are subject to change based on quality control analysis; Pre-Treatment = Day 0, Post-Treatment